The US military has as many as 750 overseas facilities, including 19 permanent or semi-permanent military sites in the Middle East. Yet, the Iran war has demonstrated that these bases can be liabilities as much as they are assets. Recent reports on damage to Naval Support Activity Bahrain and other key sites in the Gulf are a case in point. Other American military sites, including US bases in Spain, have had limited operational capacity due to restrictions imposed by host countries. What do these developments mean for the future of US military bases abroad and Washington’s ability to wage war?
July’s Reimagining US Grand Strategy roundtable brought members of the foreign policy community together to evaluate how access to foreign bases influences US national security decisions. Two guest speakers provided opening remarks on how overseas bases support US power projection capabilities and influence military access in war and peacetime, as well as the alliance politics of basing access. The group then discussed how the fallout from the Iran War will affect Washington’s future basing network and the calculus of its host countries.
Brian Blankenship, Assistant Professor of Political Science, University of Miami
When several NATO allies restricted Washington’s use of military bases during the Iran war, it was a reminder that hosting US forces is a bargain that allies can renegotiate at any time. The United States leans on allies to host its foreign-deployed forces to project power abroad, but hosting can be costly for allies, who can face blowback from US adversaries or domestic opposition. Because allies remain sovereign over their own territory, they can always limit US access, whether through eviction, as the Philippines in 1992 did, or by restricting their use for specific contingencies, as some NATO members have done during the Iran war.
That risk is not distributed evenly. Some hosts value US presence for its own sake, whether because it supplements their own defenses and acts as a “tripwire” that triggers follow-on forces, or because it enables the US to react to regional threats. Others host in exchange for compensation, such as foreign aid or other favors. Base relationships are more durable in the former. As long as allies see a US presence more as a hedge against adversary threats to their security than a cause of them, base restrictions are less likely.
More broadly, to the extent that perceptions of the US shape allies’ willingness to host American forces, it is more likely that allied reluctance will come from worries about US recklessness than from doubts about Washington’s willingness and ability to defend them. Allies might hope the latter can be offset by hosting US forces. South Korea, for example, resisted troop withdrawals through the 1970s despite doubting US reliability; Poland has pushed for a permanent US base.
The nightmare scenario for allies is one where the United States simultaneously drags them into conflict and fails to protect them. This is generally less likely to hold among allies that already have a very severe perception of threat, as in Eastern Europe and Northeast Asia, than it is among allies further from threat, as in Southern Europe. The bases Washington should worry about losing are in countries that need it less.
Christopher Preble, Senior Fellow and Director of the Reimagining US Grand Strategy Program, Stimson Center
Americans have grown accustomed to a fire-ready-aim approach to the use of force. With US military personnel stationed at hundreds of bases and other facilities across the globe, nearly any problem is “in range,” so to speak.
For hawks, the omnipresence of American military power, and the speed with which it can be employed, is an unassailably good thing. This foreign presence acts as a deterrent, they say. When bad actors know that they might be on the receiving end of an American-launched Tomahawk cruise missile or apprehended in the dead of night by a stealthy SEAL team, they are less likely to act badly. And for those who can’t be deterred, imprisonment or death is always just a few hours away. From this perspective, speed is always of the essence, and deliberation is a luxury that we cannot afford.
Americans who are less enthusiastic about militarized coercion as the principal instrument of US foreign policy have long struggled to rein it in. Successive Congresses have mostly shirked their responsibility to check the executive branch’s power — and especially when it comes to waging war.
The deliberate stationing of US forces on foreign bases poses an additional challenge to restoring the balance of power. When American servicemen and women are at risk of coming under attack, this often becomes a justification for the supposed preemptive use of force. Such anticipatory self-defense circumvents anything approaching a national debate.
In the present moment, therefore, the US military is able to act in nearly any part of the world, with minimal advance planning. If the President sees danger — or merely claims he does — no one, and nothing, can stop him.
At least not yet. The Iran war and its aftermath, though, might ultimately prompt a long-overdue change. For one thing, those countries that have hosted US forces may rethink whether the costs and risks are offset by the benefits.
But the US shouldn’t hand that decision over to a handful of princes and emirs. Ending the permanent forward presence of most US forces, and denying this president, and future presidents, a potential pretext for military action, is a first step. In the future, when the United States chooses to go to war, it should do so only after a thoroughgoing debate of the costs and risks, and only after other solutions short of the use of force have been exhausted.
Nathan Freier, Adjunct Faculty, University of Minnesota’s Technological Leadership Institute; Non-Resident Senior Fellow, Atlantic Council; Non-Resident Senior Research Associate at the Center for International and Security Studies at Maryland
The ever-expanding commitments of US global strategy is a byproduct of the post-Cold War and post-9/11 environments. American military superiority and freedom of action were rewards at the end of the Cold War. Since Sept. 11, 2001, though, these rewards have consistently run up against growing perceptions of vulnerability among US policymakers. The need to preserve our post-Cold War advantages and simultaneously limit any and all vulnerabilities has led US strategists to confuse “must dos” with “can dos.”
Combatant Commands (COCOMs) take cues from Washington but operate as six regionally distinct military powers — with all the demands and resource requirements associated with a sovereign state. By virtue of their wide-ranging responsibilities, and fueled by Washington’s perpetually expanding global strategy, COCOMs have worked to maintain and expand their access to guard against a systemic perception of vulnerability. To be clear, they are doing their job. Yet, by doing so, they may be guilty of reinforcing as many “can dos” as “must dos.”
The Trump administration’s unpredictable, transactional, and frequently coercive approach to national security and defense has created more challenges for rationalizing “must” and “can dos.” Trump’s approach to Europe sows distrust and uncertainty in areas where the US needs access to operate worldwide and to counter an aggressive Russia. While opening new opportunities in Central and South America, the Trump approach is expanding the US presence of limited global utility to address sub-strategic criminal challenges. Where US access and presence have most recently been used for operations in the Middle East, the Trump administration’s approach has generated manifest insecurity and cost for host nations. And in the Indo-Pacific, where presence and access are essential to counter China, the Iran war lays bare the high risks that partners face if they choose to host American forces and capabilities.
American policymakers already risked overextension given our post-9/11 penchant for an expansive strategy driven by the perception of increasing vulnerabilities. COCOMs contributed to the challenge by responding to Washington’s prior strategic choices. In response, they perpetually expanded their perimeter to cover down on as many “must” and “can dos” as they could. The Trump Administration’s new irregular approach further complicates US strategic planning.
Future decisionmakers appear to have two options going forward. The US can either buy back presence and access or regain position through some form of political and economic coercion. The first may be cost prohibitive — at some point, resources will run dry. The second is unsustainable as it sacrifices durable collaboration for near-term advantage. I would suggest a third way based on meaningful consideration of real strategic priorities, collaboration with partners based on common interests and shared threat perceptions, and, most importantly, a ruthless bias among all the “must dos” versus all the “can dos.”
Mir Mohiuddin, Former Intern of the Reimagining US Grand Strategy Program, Stimson Center
US basing access in states formerly colonized by key US allies (e.g. France and the United Kingdom), can be influenced by diplomatic relations between such allies and the host states. Recently, because of bilateral disputes premised on decolonization, in which Washington is not directly implicated, the US has withdrawn from military bases in the West African Sahel. The US may also soon confront an internationally agreed deadline for its control over Naval Support Facility Diego Garcia, a strategically important UK-US base in the Indian Ocean.
In 2024, the US handed over its last military base in Niger, after Niger severed security ties with France, its former colonial power, and instead turned to Russia. The ruling Nigerien military junta, which seized power in a 2023 coup d’état, has blamed France for allegedly sponsoring regional insurgents (or terrorists). Russian (dis)information operations have bolstered these anti-colonial narratives, undermining France’s historical sphere of influence in West Africa. Since US military forces in Niger became entangled in growing anti-French sentiment, their withdrawal symbolized a reclamation of sovereignty in the junta’s public diplomacy.
In 2025, the United Kingdom signed an international agreement to cede sovereignty of the Chagos Islands to Mauritius (a former UK colony). Earlier, in 2019, the International Court of Justice had delivered a non-binding Advisory Opinion, finding that “the process of decolonization of Mauritius was not lawfully completed,” and that “the United Kingdom is under an obligation to bring to an end its administration of the Chagos Archipelago as rapidly as possible.” The 2025 UK-Mauritius agreement, not yet ratified, allows for the United Kingdom to retain jurisdiction in respect of Diego Garcia, under a 99-year lease, in exchange for payments (or reparations). Reportedly dissatisfied with the agreement, the Trump Administration has been drafting a proposal to purchase the Chagos Islands to maintain control over Diego Garcia in perpetuity.
Ultimately, overseas US military bases can become embroiled in disputes between formerly colonized host states and the powers from which they gained independence. US bases can turn into symbolic scapegoats (such as Niger) or bargaining chips (for example, Diego Garcia), leading to the potential end of basing access.
Marcel Sebastián Anduiza Pimentel, Non-Resident Fellow, Institute for Global Affairs at Eurasia Group
The military access debate is conducted almost entirely in Eurasian terms. Yet, historically, the Western Hemisphere — and the regions of Central America and the circum-Caribbean in particular — is where the US first built its access system after the 1898 Spanish-American War, and where that presence has deeply evolved over a longer period of time, more so than in other regions (with perhaps the exception of some island-nations in the Pacific). Understanding how and why that presence in Central America and the circum-Caribbean changed over time, and how it relates to more recent successive cycles of base realignment and closure followed by new waves of base rebuilding, casts light on the situation now being experienced in other regions, where the question of access is being actively debated.
The US’s presence in the region, its expansion and retreat over the 20th century and into the 21st, proceeded through cycles of convergence and blowback: treaty ratification, asymmetric bargaining, and the results of bilateral economic relations that the economic historian John Coatsworth described, in his book of the 1990s, as those between the Clients and the Colossus. Across these cases, host states, with “excessively close and subordinate ties to the United States,” have allowed and then revoked access for much the same reasons analysts now list as hypothetical future risks in other continents: sovereignty, reputation, or blowback, the prospect of becoming a target, whether domestically or internationally.
The access system is now being rebuilt in the region, taking into account this old history, as part of a broader project to create new sites and revive earlier ones — Puerto Rico, Panama, Ecuador, Trinidad and Tobago — under different guises and new modalities: reactivating, reopening, or returning under new status-of-forces agreements, with logistical access justified in terms of cooperative security locations, rotational deployments, airbase military transit, and temporary presence. The region’s record complicates the conclusion that access denied would mean the end of American projection of power. In the Caribbean and Central America, despite its strategic proximity to the United States, denial meant not an end to projection, but a change in its form. In most countries in the region, large permanent installations gave way to lighter, more provisional, kinetic arrangements, barring a few cases.
Where access is currently most being contested in Europe and the Asia-Pacific region, the more likely near-term outcome may not be outright denial but substitution, following a similar trajectory in the Western Hemisphere: a shift toward forms of presence and access that are less formal, less durable, and less noticeable to the processes through which such commitments are ordinarily reviewed in host countries. That is a subtler outcome, and a harder one to measure, which is reason enough to look first at subregions in the same hemisphere, where these historical patterns of transition have already taken place.
