Argument

What to Do With U.S. Forces in the Persian Gulf

As the United States leaves Afghanistan, the question of troops in the Middle East to support the Afghan mission looms large.

By Steven Simon, professor in the practice of international relations at Colby College. He served on the NSC staff in the Clinton and Obama administrations, and Richard Sokolsky, a non-resident senior fellow at the Carnegie Endowment for International Peace.
U.S. Army troops from the 10th Mountain Division collect their duffels after returning from a nine-month deployment in Afghanistan to Fort Drum, New York, on Dec. 8, 2020.
U.S. Army troops from the 10th Mountain Division collect their duffels after returning from a nine-month deployment in Afghanistan to Fort Drum, New York, on Dec. 8, 2020. John Moore/Getty Images

In 1971, Alain C. Enthoven and K. Wayne Smith, two of former U.S. Secretary of Defense Robert McNamara’s so-called “whiz kids,” wrote a book titled How Much is Enough? Shaping the Defense Program. The subject was defense spending. And the title promised an answer, but like other perennials, the question still pops up multiple times every year in public policy decisions. It’s a simple and important one, but there remains no black and white answer.

U.S. President Joe Biden’s decision to withdraw all U.S. forces from Afghanistan before Sept. 11 is a twofer: Since some U.S. forces deployed to the Persian Gulf are there to support U.S. operations in Afghanistan, they can be withdrawn and repurposed for other missions as the United States ends its military engagement in Afghanistan. However, the Biden administration will continue to struggle with how much is enough regarding the thousands of other military personnel in the Persian Gulf it inherited from its predecessor, including those dedicated to supporting U.S. military operations in Iraq.

This is, of course, not a new debate; but over the past several years, the chorus calling for ending the United States’ endless wars in the Middle East have cast a brighter light on the value of sustaining the country’s historic role as the guarantor of security in the Persian Gulf. As of yet, no consensus has emerged.

As is almost always the case in Washington policy debates, positions have become hardened around two extremes: Pack up the troops and go home, or stay the course. The answer, unsurprisingly, lies somewhere in between. As long as the rest of the world—if not the United States—remains dependent on oil and gas exports from the Persian Gulf, the United States and Iran are in conflict, and there is a potential for Iran to go nuclear or attack U.S. allies and partners in the region, the United States will need to maintain a military presence as a hedge. This military footprint, however, can be smaller than it is today.

Decisions about how small, exactly, should be based on a hard-headed calculation of U.S. interests in the Persian Gulf; an understanding of threats to those interests; and an assessment of the benefits, costs, risks, and implications of each policy choice. So what should a racking and stacking of those factors look like?


The champions of U.S. military disengagement from the Persian Gulf make several arguments.

First, the United States has no vital interests in the Persian Gulf. The region’s strategic importance to the country is declining primarily because of its growing energy production and global energy market diversification.

Second, the main threats to regional security and stability are internal, stemming from state weakness and dysfunctional governance; U.S. military forces are ill-suited to address these sources of conflict.

Third, core U.S. interests in the region are not currently endangered and can be safeguarded at a lower cost and with fewer risks and military resources. The United States does not need to maintain a permanent peacetime military presence to protect the free flow of oil, defend Israeli security, combat jihadist terrorism, or prevent the emergence of a hostile regional hegemon.

Fourth, the United States would save a considerable amount of money if forces in the Persian Gulf were withdrawn to the United States.

Fifth, the capabilities the United States deploys in the Persian Gulf would be better allocated to the European and Indo-Pacific theaters to wage great-power competition with Russia and China.

Finally, limiting the exposure of U.S. military forces in the Persian Gulf would reduce the risk of their involvement in other countries’ internal conflicts; as long as the United States operates forces in the region, the argument goes, it will be too tempting for U.S. leaders to pursue military solutions to foreign-policy problems.


Proponents of maintaining the military status quo contend the financial and strategic benefits of military retrenchment have been exaggerated. Their argument goes as follows:

First, most U.S. forces in the Persian Gulf support U.S. military operations in Iraq and Afghanistan and are performing non-combat roles, such as training, advising, and assisting local forces. As long as the United States maintains its missions in these two countries, there is only a limited scope for force reductions.

Second, the deployment of U.S. forces in the Persian Gulf was never about ensuring U.S. access to its oil supplies—given its ability to get oil elsewhere—but rather about access for the United States’ friends, allies, and partners around the world. Although the Persian Gulf may be of declining strategic significance to the United States, Washington still has important interests in maintaining the stability of global energy markets and deterring Iranian adventurism.

Third, instability would threaten U.S. security partners and potentially create more safe havens for groups seeking to attack the United States while Iran’s assertiveness and geopolitical aspirations in the region could spark a conflict with the United States itself.

Fourth, U.S. forces stationed in Gulf Cooperation Council states suffer very few casualties, and their current force posture is relatively small and cheap to maintain in the context of a $740 billion 2021 fiscal year defense budget request. Withdrawing these forces would not save any money unless they are dropped from the force structure, which is highly unlikely. Moreover, because Persian Gulf states provide outstanding training facilities and bear most of the costs of supporting U.S. forces, relocating these assets would cost the Pentagon more money. The current U.S. military presence is politically sustainable—it does not engender local hostility, threaten domestic stability, create political problems for host countries, or present a serious risk of terrorist attacks.

In addition, the champions of the status quo contend the potential strategic risks of military disengagement have been underestimated. It could frighten U.S. allies, and the more vulnerable those allies feel to attack, the more likely some of them will act aggressively against Iran. In other words, U.S. forces are in the region not only to deter Iran but also to restrain U.S. partners.

Disengagement could also, they argue, erode credibility of the U.S. extended conventional deterrent. Tehran could decide to act more aggressively because it sees U.S. retrenchment as evidence that the United States is no longer committed to defending Gulf states. These states, led by Saudi Arabia and the United Arab Emirates, could likewise decide the United States is no longer a reliable security partner and develop their own nuclear programs, spurring a regional arms race.

If the United States left, it would also have less leverage on oil issues with Saudi Arabia in those (admittedly extreme) circumstances when a sudden, steep, and sustained drop in oil supplies sends the global price of oil through the roof and the U.S. president is willing to turn the screws on his counterpart to ramp up Saudi oil production to lower prices.


There are good arguments on both sides, but the key driver of the current U.S. force posture is the potential for conflict with Iran. Thus, the only safe exit ramp for U.S. forces out of the Persian Gulf hinges on a long overdue resolution of the nuclear and regional issues that have vexed the U.S.-Iranian relationship for years. But as long as those two countries are in a state of conflict, U.S. military access to regional bases and a military presence will be necessary. The United States does not, however, need to maintain all the forces it currently stations in the Persian Gulf once U.S. military operations in Iraq and Afghanistan have wound down or been terminated.

A quick tour of the Gulf horizon suggests the United States should maintain its modest military presence in Bahrain unless its presence becomes a major source of instability. If the United States is going to maintain regular offshore naval deployments in the Arabian Sea, as it should, pulling up stakes in Bahrain would not be prudent or cost effective.

U.S. forces that were temporarily deployed to Saudi Arabia over the past two years should be withdrawn while air and missile defenses of critical infrastructure should be upgraded.

Downsizing some bases and trimming military personnel in Kuwait, the UAE, and Qatar would be justified by the end of U.S. expeditionary operations in Iraq and Afghanistan.

These recommendations are based on our judgment that strategic and financial benefits of removing all U.S. forces from the Persian Gulf have been exaggerated and the risks associated with full military disengagement have been understated. The United States’ modest military presence in the Persian Gulf is affordable and politically sustainable; it also provides some value—although admittedly difficult to quantify and dependent on a given administration’s reputation—in deterring Iranian adventurism and reassuring U.S. allies in the region of its security commitment. It also enables a swift response to a range of military contingencies.

The United States’ core interests in the region can be protected with a smaller and more rationalized military presence, supplemented as necessary by rotational U.S. force deployments. These modest drawdowns will be criticized as too timid by advocates of military retrenchment while hawks on Iran will attack any withdrawals as a U.S. retreat from its leadership and a betrayal of its security partners and allies in the region. This very basic stance will ensure the United States is not caught unprepared in an area where it still has important—if diminishing—interests and which could offer unpleasant surprises as long as the United States and Iran have a hostile relationship. Until they reach some kind of compromise, a complete reduction of the United States’ presence will be constrained by the ancient adage, “if you want peace, prepare for war.”

Steven Simon is professor in the practice of international relations at Colby College. He served at the State Department and as National Security Council staff and is co-author of The Pragmatic Superpower: Winning the Cold War in the Middle East. His new book, The Long Goodbye: The United States and the Middle East From the Islamic Revolution to the Arab Spring, is forthcoming.

Richard Sokolsky is a non-resident senior fellow at the Carnegie Endowment for International Peace. He served in the State Department for 37 years and was a member of the Secretary of State’s Office of Policy Planning from 2005 to 2015.