Why Overseas Military Bases Continue to Make Sense for the United States
Every president in the post-Cold War period has sought to close U.S. military bases overseas, particularly in Europe. President Bill Clinton oversaw some of the most significant reductions. President George W. Bush continued the trend, downsizing some several hundred bases and returning tens of thousands of troops home. President Barack Obama withdrew two Army brigades from Germany in 2012, before later reversing the trend after Russia invaded Crimea. Most recently, President Donald Trump initiated a plan this year to remove some 12,000 U.S. troops from the country, before Congress blocked the move. Whether it was to realign American strategy, save dollars while avoiding taking jobs out of congressional districts, or settle scores after a perceived foreign policy wrong, presidential administrations have traditionally taken aim at the United States’ overseas bases to make ends meet.
The push to slash United States’ overseas bases is not going away anytime soon. The Chairman of the Joint Chiefs of Staff Gen. Mark Milley recently remarked, “Large permanent U.S. bases overseas might be necessary for rotational forces to go into and out of, but permanently positioning U.S. forces I think needs a significant relook for the future.” Voices on the left and right have proposed downsizing America’s overseas footprint. A serious rethink of U.S. basing in the Middle East is underway. Even inside the Defense Department, there have been calls to move away from permanent bases to projecting power from the United States or deploying forces forward on a temporary basis. At the heart of much of this opposition is a belief that overseas bases are anachronistic, premised on outdated geostrategic assumptions and outmoded forms of warfare. And yet, while the United States’ overseas bases may date to the aftermath of World War II, the twin rationales of deterrence and reassurance for stationing troops — especially land forces — overseas remain valid in the 21st century.
Outdated Geostrategic Assumptions and Outmoded Forms of Warfare?
The case for the permanent stationing of forces rests on the complementary logic of deterrence and reassurance. As Thomas Schelling noted in his classic Arms and Influence, the 7,000 Americans garrisoned in West Berlin helped keep the city free during the Cold War by being a tangible signal to both the Soviet Bloc and to its NATO allies of American commitment to fight for Europe. A half century later, this same strategic logic still holds true. Research still suggests that positioning ground forces forward — particularly less mobile heavy forces — remains one of the best options to deter adversaries and reassure allies. Unsurprisingly, the bipartisan National Defense Strategy Commission found, “If the United States desires to avoid military conflict in these regions it should ensure there is a capable day-to-day posture in both theaters to deter adversaries and engage in prompt escalation control.” Today, however, the traditional arguments for having U.S. military bases overseas — deterrence and reassurance — are under increased scrutiny.
Of the two rationales, reassurance is, perhaps, the more politically controversial. After all, why should the United States need to reassure its allies in the first place? Why can rich, advanced countries not provide for their own defense? American politicians often raise such concerns. Indeed, Obama labeled American allies “free riders.” Trump, similarly, criticized the United States’ NATO allies for being “very far behind in their defense payments” and, instead, sticking the United States with a bill. He even provocatively claimed that “our allies take advantage of us far greater than our enemies.” As the argument goes, the U.S. military presence encourages allies to rely on American security guarantees rather than investing in their own defense. The more permanent the presence, the stronger the perverse incentive becomes.
By contrast, doubts about the necessity of overseas bases for deterrence stems more from operational considerations. While this school agrees that China, Russia, and other adversaries need to be deterred, proponents argue that there are cheaper, more operationally sound, and less provocative ways to deter adversaries than through permanently stationing troops overseas. For example, some claim that stationing American servicemembers overseas costs tens of thousands of dollars more per servicemember than stationing troops at home and that closing overseas bases can save $50 to $150 billion. Others note that modern technology — from longer range aircraft and missiles to new domains like cyber and space — will allow future wars to be fought at range, making overseas bases strategically unnecessary and leaving soldiers and their families stationed at these bases increasingly vulnerable to attack. Finally, still others argue that permanent bases inflame, rather than ease, tensions. After all, American adversaries — from Osama bin Laden to Russia and China — have all bristled at the presence of U.S. forces overseas in the past, and permanent basing only ensures enduring conflict.
The Enduring Case for Overseas Basing
On closer inspection, neither the political nor the operational critiques of American overseas basing, however, stand up to scrutiny. This perverse incentive claim should first be placed in its historical context. In the aftermath of the World War II, the United States and its allies demilitarized Germany to preserve the peace in Europe. As NATO’s first Secretary-General Lord Hastings Lionel Ismay quipped, the alliance was designed to “keep the Soviet Union out, the Americans in, and the Germans down.” Arguably, the policy worked only too well. While Germany became the economic powerhouse of Europe, it underspent on defense, particularly after the Cold War. If Germany “free rides” today, it is not primarily because of the American military presence in-country. Indeed, Germans remain ambivalent as to whether American bases in their country actually enhance their security. Rather, many Germans doubt whether military force is necessary to maintain the international order in general.
Instead, threats drive defense spending, not American presence. Since the 2014 invasion of Ukraine, the key determinant of many European countries’ defense spending has been their geographical proximity to Russia. The crisis in Eastern Europe prompted many frontline countries to meet NATO’s 2 percent of gross domestic product target for defense spending after years of paltry budgets, despite an almost continuous American military presence in the region for years. For example, Poland — the current focus of the U.S. Army’s forward posture in Europe — upped its defense spending by over 11 percent last year alone. And the same is true in Asia. While the legacy of World War II created deep-seated pacifism among the Japanese public, the country posted some of its largest increases in defense spending in decades because it fears Chinese — and, to a lesser extent, North Korean — belligerence, even though it remains home to tens of thousands of American servicemembers.
Estimates of how much the United States could save by closing bases depends on how we count costs and what, if anything, replaces permanent overseas presence. Some models presume dramatic changes to American strategy — such as cutting, rather than relocating, the troops — that go well beyond what policymakers and many members of Congress currently view as prudent, especially in a world with intensifying great-power competition. The actual policy proposals tend to be more modest: swapping permanently stationed forces for a rotational presence, whereby units deploy overseas from the United States for periods of time. Such policies may not actually save money. After all, sending troops abroad costs money, while many of the bases in Europe and Asia are already built (and, hence, are sunk costs) and the infrastructure is also subsidized by host governments. Indeed, an Army War College study found that the Department of Defense would spend $135 million more per year to rotate a single brigade to Germany from the United States than simply to forward station the unit there.
The vulnerability argument is similarly unpersuasive. Despite all the technological advances in warfare, wars cannot be fought entirely at range. Especially in land-centric theaters like Europe, ground forces are still the key to deterrence by denial and preventing fait accompli. Even in air- and maritime-centric theaters, however, like the Indo-Pacific, keeping forces closer to the fight simplifies logistics challenges and increases combat power by reducing the time spent in transit. And physical presence, arguably, also goes a long way toward reassuring the commitment of U.S. allies, by signaling not only the capability but, more importantly, the political will to fight in ways long range systems cannot.
If one accepts the premise that forces still need to be forward-deployed, then the additional risk incurred by permanently basing forces overseas — versus deploying them on a temporary basis — becomes less clear. True, overseas bases are vulnerable to attack, but so too are rotational forces. After all, there are only a limited numbers of locations that can support tanks, armored vehicles, field artillery pieces, and thousands of soldiers — especially in heavily populated places like Europe. Given the administrative and logistical burdens that come with moving large numbers of forces around crowded theaters, most deployments are also coordinated well in advance, raising questions of just how “operationally unpredictable” these forces actually are. Above all, rotational forces trade the vulnerability of large overseas bases for the risks of needing to flow forces through a handful of air and seaports.
Moreover, whatever additional risk there is needs to be weighed against a host of other operational benefits that favor forward basing. As a rule of thumb, deploying a single unit ties up three units — one deployed, one getting ready to go, and another recovering from having gone. By contrast, stationing a unit abroad relieves this pressure and increases readiness, since units can train, operate, and maintain their forces in one location. Living overseas also can be an attractive lifestyle option for servicemembers and an added incentive to join, or remain in, the military, whereas frequent deployments away from family can harm retention. Above all, forward basing keeps forces nearer to a potential fight and can allow them to respond quickly in the event of crises. In sum, the survivability of overseas bases points to the need to harden these facilities, not divest from them entirely.
Finally, there is a claim that permanent stationing is unnecessarily provocative. There is a thin line, however, between provocation and deterrence. Both involve altering rivals’ perceptions and whether any given military’s actions provoke or deter often is only known in hindsight. And yet, it is hard to see why permanently stationing forces would be that much more provocative than rotating forces through a given location, particularly on a continuous basis, or building a capability for rapid global power projection. If anything the latter may even be more destabilizing, since it reduces adversary warning timelines.
“America Is Back”
For the moment, the incoming Biden administration seems less enthused with cutting forces from Germany. That said, there will likely be downward pressure on defense budgets thanks to the COVID-19 pandemic. And if history is any precedent, overseas basing will be an attractive, politically expedient target to reap potential savings. Such a move, though, would be a mistake.
If a Biden administration wants to signal that “America is back,” after four years of an “America First” foreign policy, U.S. military bases around the world could provide a concrete signal of America’s enduring commitment to its alliances to friend and foe alike. While the merits of basing in Germany versus Poland, or in Japan versus Guam, should be open to debate, the underlying twin logics of deterrence and reassurance behind permanently stationing American forces overseas remain operationally, economically, and strategically as sound as ever.
Raphael S. Cohen is a senior political scientist at the nonprofit, nonpartisan RAND Corporation; the associate director of the Strategy and Doctrine Program, Project AIR FORCE; and a former active duty Army officer.