The Trouble With Permanent Alliances

The Trouble With Permanent Alliances

Why America’s Pacts Should Have Expiration Dates

Naman Karl-Thomas Habtom

April 13, 2026

• More by Naman Karl-Thomas Habtom

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For the past 75 years, the United States has pursued a historically anomalous strategy toward alliances. Traditionally, alliances were forged as highly contingent, time-bound partnerships, but after World War II, the United States went about establishing permanent ones, including NATO and bilateral alliances such as those with South Korea and Thailand. This practice had some use during the Cold War, because it consolidated U.S. dominance on its side of the Iron Curtain. But after the Soviet Union collapsed in 1991, the United States found itself bound by a set of alliances that sacrifice its adaptability and endanger its security.

Temporary alliances are the more sensible norm. Throughout most of history, such partnerships were created to serve concrete diplomatic and strategic purposes. Indeed, the United States already treats some of its purportedly permanent alliances—such as the 1947 Rio Treaty, a collective security agreement covering most of the Western Hemisphere—as effectively defunct, acknowledging that the d interests that motivated the arrangements have expired. But for the most part, Washington still clings to the notion that alliances are eternal, sacrosanct pacts that are ends in themselves. By continuing to pledge unconditional defense assistance to allies across Europe and large parts of the Indo-Pacific, the United States is failing to adapt. President Donald Trump’s threats to ignore or unilaterally withdraw from alliances, however, is no better. It simply alienates existing allies and potential partners in exchange for dubious short-term benefits.

To maintain credibility in an increasingly multipolar world, the United States will need to formally renegotiate all its permanent alliances, abandoning some and reestablishing others as time-bound pacts, ensuring that its defense obligations reflect present conditions and future threats rather than a Cold War dynamic. Washington need not come up with new paradigms to do this. Historical alliances as well as existing arms control agreements and nontreaty security partnerships can provide blueprints for alliances that are fit for purpose. Although existing U.S. allies may fear such a move, they shouldn’t. Restructuring U.S. alliances so they are more limited and brief will serve their interests, too.

JUST IN TIME

In the Westphalian nation-state era, countries generally treated alliances as narrow in scope and highly contingent. They were formed to respond to wars, not anticipate them decades in advance. This kind of ad hoc coalition building made states responsive to present threats without binding their futures. Alliances were first and foremost instruments of statecraft and warfare, not ends in themselves.

For two hundred years, from the early sixteenth century to the mid-eighteenth century, Austria and France struggled for supremacy over Europe. Rivalry between these powers was an immutable fact of the continent’s political life—until it wasn’t. In 1756, the French-Habsburg rivalry gave way to an alliance; Prussia and the United Kingdom were emerging as powers in their own rights, and Paris and Vienna freely abandoned their previous partnerships with Berlin and London, respectively, to contend with the change. In the eighteenth, nineteenth, and twentieth centuries, European states formed coalitions only as imminent threats—such as Napoleonic France or Nazi Germany—emerged. An alliance created for the sake of one war neither predicted nor committed future alignments. This approach reduced countries’ risk of being dragged into a conflict because of the whims of an ally.

Until the 1940s, the United States also largely avoided long-term alliances. A 1778 treaty made France the United States’ first official ally. But by 1793, President George Washington had already effectively voided the treaty with his Proclamation of Neutrality, which sought to keep the United States from getting mired in the French Revolutionary Wars. Washington correctly identified that U.S. interests were no longer aligned with French ones, especially as the French Revolution threatened to engulf all of Europe. Washington made explicit his belief that alliances must be crafted with care and continually reconsidered in his 1796 farewell address, composed with the help of Alexander Hamilton and James Madison: “It is our true policy to steer clear of permanent alliances with any portion of the foreign world. . . . We may safely trust to temporary alliances for extraordinary emergencies.”

Until the 1940s, when it did strike military partnerships, the United States generally opted to join specific wartime coalitions. At the turn of the twentieth century, it entered the Eight-Nation Alliance, a coalition to suppress anti-foreign uprisings during China’s Boxer Rebellion. In January 1917, just months before the United States entered World War I, President Woodrow Wilson addressed the Senate and declared that all nations should “avoid entangling alliances which would draw them into competitions of power, catch them in a net of intrigue and selfish rivalry, and disturb their own affairs with influences intruded from without.” And when the United States did enter the war, it did not formally join the Allies but became an “Associated Power,” maintaining a degree of independence in its war aims.

Even NATO’s founding charter acknowledged that alliances must have temporal limits: Article 13 of the North Atlantic Treaty bound its founding members for only 20 years, after which any member could withdraw as long as it gave a year’s notice. After 1969, NATO became an open-ended alliance, with legal procedures for withdrawal but no formal limit to its duration. Similarly, the founding document of the Warsaw Pact—created to consolidate Soviet influence over Eastern Europe—stated that “the present Treaty shall remain in force for twenty years,” and added a provision allowing for a ten-year extension.

ENDLESS CHAINS

During the Cold War, however, the United States changed tack fundamentally, embracing permanent alliances as a sign of global strength. Between 1945 and 1955, the United States signed mutual defense treaties with 45 countries. Some were undertaken bilaterally (such as with Japan and the Philippines), and others—such as the now defunct Southeast Asia Collective Defense Treaty—were larger pacts. These treaties did not preclude withdrawal (typically requiring a one-year notice period), but they were designed to be indefinite. These alliances were primarily about ensuring American primacy over large parts of the globe: the Rio Treaty enshrined the Monroe Doctrine in an international agreement, NATO affirmed Washington’s centrality to Western European security, and various treaties in the Indo-Pacific entrenched the United States as the region’s leading influence. Instead of striking alliances to respond to an ongoing war, U.S. leaders opted to set down in peacetime the United States’ perpetual military commitments. Permanent alliances also ensured that foreign governments remained firmly within its sphere of influence. In a bipolar world, this allowed for the consolidation of blocs.

In truth, however, the United States’ readiness to support a country at war was always defined by perceived interests, not treaty commitments. Washington regularly aided nontreaty allies, assisting Seoul during the Korean War, for instance, well before it signed a mutual defense pact. Kuwait was similarly liberated by a U.S.-led global coalition, not by a bilateral defense pact. And billions of dollars of military aid to Israel and Ukraine reflect policy decisions, not treaty obligations.

Although supporters of military alliances may view them as inviolable, the United States has ended such agreements unilaterally. After recognizing the People’s Republic of China in 1979, the Carter administration terminated the United States’ mutual defense treaty with Taiwan, substituting direct defense commitments with strategic ambiguity. It has also effectively nullified treaty commitments through diplomatic signaling (such as by suspending its treaty obligations with New Zealand in 1986 without abrogation, after the country decided to become a nuclear weapons–free zone), troop withdrawals (such as from South Vietnam by 1973), and silence. When the United States backed the United Kingdom over Argentina during the Falklands War, it exposed the hollowness of the Rio Treaty but suffered no significant long-term strategic consequences.

But despite this practical flexibility, in the post–Cold War era, permanent alliances have inflicted major damage on the United States. They have predetermined the country’s adversaries: although pacts such as NATO and Washington’s bilateral treaties in the Indo-Pacific do not explicitly name the enemy, they are still largely defined by antagonism toward Moscow and Beijing. A peaceful, pragmatic, and stable relationship among the three nuclear great powers ought to have taken precedence over support for countries on their peripheries.

Between 1945 and 1955, the United States signed mutual defense treaties with 45 countries.

Within alliances, permanence has made it harder to compartmentalize issues. The United States and its dependent partners can hold one another hostage. Washington can demand significant political and economic concessions in exchange for military support, and allied capitals can drag the country into confrontations that U.S. leaders then feel obliged to double down on to maintain credibility. British and French leaders pushed the United States to undertake its 2011 military intervention in Libya. How could the United States stand by, U.S. Secretary of State Hillary Clinton explained, when “France and the United Kingdom and other Europeans and the Arab League . . . were saying, ‘You’ve got to do something’?” Similarly, a desire to sustain a permanent alliance led countries such as Denmark and the Netherlands to join the United States in pursuing disastrous wars such as the 2003 invasion of Iraq.

The recent panic in European capitals about a reduction in U.S. commitments to the continent suggests that these countries think permanent alliances were in their interest. But in fact, European countries should want revisions. Indefinite U.S. security commitments unintentionally created moral hazards: NATO membership permitted countries along the alliance’s eastern flank to let their bilateral relations with Russia atrophy. By convincing allies that it would come to their defense, Washington emboldened politicians across eastern Europe to pursue more reckless foreign policies than they might otherwise have chosen if they knew they would have to deal alone with the repercussions of their actions.

The Biden administration put considerable pressure on allies in Europe and Asia to align with Washington’s efforts to contain China, such as by attempting to push certain Chinese telecommunication firms out of allied markets. These measures were not implemented in order to address an imminent threat faced by members of any particular alliance but rather to ensure American primacy. Reducing their dependence would make U.S. allies less vulnerable to these kinds of tactics. Consider how Saudi Arabia’s inability to win a defense treaty with the United States turned out to be a blessing in disguise: it was able to pursue a less zero-sum approach to its partnerships. It subsequently signed a strategic mutual defense agreement with Pakistan, making it more immune to foreign pressures on nonbilateral issues such as Israeli-Saudi normalization.

The Trump administration’s hostility toward some U.S. allies—and its lack of strategic clarity about its priorities—simply require these states to imagine a future without the United States as an ally. But because any effort to replace U.S. military capabilities or establish new security doctrines will take years, a new kind of time-limited defense treaty could serve as a bridge between the status quo and more self-reliance.

LIMIT ORDERS

The United States shows it can maintain multidecade partnerships without the formality of mutual defense treaties. It has used arms sales, basing rights, foreign aid, and joint military exercises to effectively consolidate relationships with strategically situated countries across the globe. Now it needs to redesign its alliances with Australia, Japan, the Philippines, South Korea, and Thailand, as well as its commitment to NATO.

Arms control agreements offer a blueprint. Nuclear weapons–related arms agreements are frequently time-limited to reflect the fact that technological and geopolitical realities are ever evolving. The first treaty that emerged from the U.S.-Soviet Strategic Arms Limitation Talks, SALT I—which was inked in 1972 and froze the total number of intercontinental and submarine-launched ballistic missiles—had a five-year duration. SALT II, signed in 1979, preserved its signatories’ flexibility by asserting that if “extraordinary events related to the subject matter of this Treaty have jeopardized its supreme interests,” either the United States or the Soviet Union could withdraw. After the Cold War, strategic arms control agreements continued to be time-limited: the New START treaty, which imposed limits on the total number of strategic warheads deployed worldwide and imposed verification measures to ensure compliance, lasted for ten years with the option for a five-year renewal. Washington’s weapons procurement and aid agreements are also time-bound. For example, the 2016 Memorandum of Understanding between the United States and Israel provided Israel military assistance for only ten years, after which each country may choose to reassess the nature of the bilateral military relationship and its future.

Washington must begin the process of transforming its existing—and still relevant—alliances along these lines. Treaties should have clearly defined expiration dates, and second-order issues, such as the scale of troop deployments and financial investments, need to be defined with greater discipline. This process will be most straightforward with bilateral treaties, such as the ones Washington already has with Japan, the Philippines, and Australia. These treaties generally have a one-year notification requirement for withdrawal; this will not be long enough to prepare redesigned agreements, so the United States should notify these allies of its intention to sunset existing mutual defense treaties over the course of five years while remaining open to negotiating new pacts to ensure an orderly transition.

Expiration dates for treaties will give allies incentives to provide for their own defense.

If the United States wishes to participate in European security, it must either treat the continent (including Russia) as a single space—and seek to replace NATO with a single time-bound structure focused on internal stability rather than an external actor—or view the continent as a continuum, if Russia is excluded. In that case, instead of one transatlantic alliance, the United States ought to pursue time-limited regional agreements that serve as a bridge to a future in which Washington joins wartime coalitions only as an act of last resort rather than as an automatic treaty obligation. If that move led NATO to cease to exist, Washington could sign treaties with countries in western and southern Europe while avoiding striking any pacts at all with states on Russia’s doorstep. The resulting reduction in treaty obligations would allow the United States to renew some European commitments without pledging to defend to all 30 European countries in NATO.

Should the European members of NATO wish to preserve the organization as a permanent institution, the United States should make it clear that it will engage with the alliance in the same way as any other non-ally. Intelligence sharing and joint exercises, such as the ones Washington already undertakes with the Association of Southeast Asian Nations, could continue in the absence of a formal alliance, but these should address specific objectives. The United States and its current allies would enter a transitional period in which the move to time-bound defense pacts occurs in stages, with some existing alliances lasting longer than others and with negotiations taking varying amounts of time. This transition would allow U.S. allies and partners to do more diplomatic groundwork to create intraregional cooperation.

A default duration of ten years for bilateral defense treaties would match standard practice for other kinds of security arrangements such as arms control agreements and weapons deals. By enduring across U.S. presidential administrations, this time frame would also ensure medium-term stability and permit enough time to negotiate renewals or prepare for a post-alliance future. Sunset clauses or periodic renewals could allow the United States and others to continually reassess priorities and threats. For high-risk allies, such as those with poor relations with Russia or ongoing disputes with China, renewal periods should be shorter or excluded, balancing the need for stability with long-term risks and paving the way for changes in Washington’s ties with either Moscow or Beijing.

The mere act of negotiating new pacts would be fruitful, pushing both the United States and its counterparties to more clearly define their military priorities. The awareness that a defense pact could end will limit the free-rider problem. Expiration dates will give allies concrete incentives to provide for their own defense instead of bickering about burden sharing. And a counterparty’s refusal to sign a time-limited alliance would also provide the United States with a way out of current commitments without having to resort to a more brash unilateral withdrawal that could harm its credibility. Depending on risk assessments, the United States could even ask for exclusivity. Such a provision, which would require an ally not to unilaterally make new alliances of its own, could prevent the complex webs of entanglements that led to the outbreak of World War I and help clarify core interests for the United States and its current NATO allies.

SHORT AND SWEET

There are real risks to changing approach. Without eternal defense pacts, U.S. influence could recede as its security guarantees expire or appear less desirable. But the existing allies with which the United States may lose some influence (such as other NATO states) are the same countries with which it can afford to lose it. States that are rapidly gaining the most power globally—such as Brazil, India, and Indonesia—do not have permanent alliances with the United States. If the United States were relieved of its excessive treaty burdens elsewhere, it would find it easier to engage these rising powers, and it would be easier for these countries to approach Washington on specific d interests if doing so did not compel them to fully align with Washington’s geopolitical approach. Some advocates of the status quo argue that the United States can leverage its vast alliance network to counter China’s immense size, but the expansion of alliances also increases the probability of tension. The divergent views on China held by Thailand and the United States, for instance, have led U.S.-Thai relations to suffer more than they would have had the two countries not been treaty allies.

Undoing the United States’ permanent alliances might also heighten the risk of nuclear proliferation. Because one of Washington’s most important offerings is its nuclear umbrella, states may feel compelled to find alternative solutions, such as producing their own nukes or hosting someone else’s. But it is already clear that permanent alliances do not necessarily prevent nuclear proliferation: both France and the United Kingdom were NATO members when they obtained their own nuclear weapons, in 1960 and 1952, respectively. The United States can also mitigate the risk of proliferation by amping up its global arms control efforts, for instance by offering preferential trade agreements in exchange for limiting the coverage of its nuclear umbrella or reducing its own nuclear arsenal as part of wider security architecture talks. Or it could offer pacts of a longer duration, such as 15 or 20 years, if an ally considering nuclear weapons voluntarily subjected itself to stringent verification and monitoring by the International Atomic Energy Agency.

Ultimately, Washington’s sprawling alliance network across both ends of Eurasia is seen by both Beijing and Moscow as a threat and a mere extension of the Pentagon’s reach. Only a significant restructure of alliances will give the United States the credibility it needs to meaningfully improve relations with these two powers—indeed, revamping its own alliances would create an opportunity to reset relations with China and Russia and could prompt them to offer concessions of their own, such as on trilateral arms controls.

The United States must recognize that because its interests and its future are not fixed, its allies must not be, either. Permanent alliances may appear to offer stability. But flexibility is the truer source of strength and security.

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