Wise leaders seek to maintain the maximum degree of flexibility in foreign policy. Commitments and strategies that make sense under one set of conditions can become problematic when circumstances change. It is imprudent and potentially dangerous to lock one’s country into rigid, long-term obligations. Unfortunately, U.S. leaders since World War II have repeatedly violated that principle. Often they have limited America’s policy options to “reassure” allies in Europe and Asia that the United States will incur any risk and pay any price to protect its security partners. That policy is not sustainable.
Such commitments have bedeviled great powers throughout history. Perhaps the most tragic example occurred during the years leading up to World War I. Europe’s major countries divided themselves into rival security blocs, the Triple Entente and the Triple Alliance. When tensions soared in 1914 following the assassination of Archduke Franz Ferdinand, the heir to the Austro-Hungarian throne, those alliances transformed an emotional but limited dispute between Austria and tiny Serbia into a continental crisis. Germany felt it must back its shaky Austrian ally’s attempt to coerce Belgrade. When Russia moved to protect its Serbian client, Germany sent warnings to Moscow. France then felt pressured to back its Russian ally, and when Germany attacked France by marching through Belgium, Britain felt obligated to enter the fray by its commitment to that tiny country. Thus was the die cast for war between the Triple Entente and the Triple Alliance.

This article appears in the January/February 2018 issue of TAC.
The process illustrated Georgetown University Professor Earl C. Ravenal’s later observation that alliances are “transmission belts for war.” A bilateral quarrel became a monstrous conflict that would consume millions of lives.
America’s founders opposed “entangling alliances” in part because they feared being locked into dangerous security commitments. In his Farewell Address, George Washington made an important distinction between permanent and temporary alliances. The United States, he said, should “steer clear of permanent alliances with any portion of the foreign world…” Such obligations would tie the republic to partners for unforeseen contingencies far into the future. But Washington acknowledged that “temporary alliances for extraordinary emergencies.” It was an astute distinction and a shrewd note of caution.
Leaving aside Woodrow Wilson’s quixotic foray into World War I, the United States followed Washington’s advice throughout the first century and a half of its existence. U.S. leaders avoided political or security commitments to other nations and involvement in conflicts unrelated to America’s own security. After the second massive disruption of the international system in little more than a generation, though, America’s perspective changed. World War II convinced policymakers that ongoing American involvement—indeed, leadership—in global security affairs was now imperative to prevent a third tragedy. The creation of NATO in 1949 symbolized a watershed policy change.
With the signing of the North Atlantic Treaty, Harry Truman linked America’s security with that of democratic Europe to prevent the Soviet Union from conquering or even intimidating those Western countries. Yet the NATO treaty didn’t establish a permanent alliance; after the initial 20 years, any member could leave with a one-year notice. Moreover, although Article 5 of the treaty did specify that an attack on one NATO member would be considered an attack on all, the language did not include an automatic obligation for the United States to go to war. Instead, the congressional power to declare war (at least theoretically) remained intact, giving Washington the option of providing support short of a full military intervention.
Still, Truman’s NATO decision generated controversy. Some feared that the protection against an automatic commitment to go to war would be nothing more than a paper barrier. Others, especially Republican Senator Robert A. Taft of Ohio, worried that America was tying itself too closely to the fortunes and problems of European countries. In his Senate speeches opposing North Atlantic Treaty ratification and in his subsequent book, A Foreign Policy for Americans, Taft stressed the advantages of preserving maximum flexibility in U.S. policy. He dubbed this the “free hand” policy.
Taft feared that despite the treaty’s hedging language, Washington was foreclosing its options. He was right. The administration’s 1951 decision to expand the U.S. occupation army in West Germany and station more than 100,000 troops on the continent created a sizable, long-term tripwire in the event of a Soviet offensive. It would be nearly impossible to avoid direct involvement in a European war if Americans were among the initial casualties. The deployment was supposedly temporary, until the Europeans could build sufficient defense forces of their own. Dwight Eisenhower, NATO’s Supreme Commander in 1951 and Truman’s successor as president, expressed the view that if those units were not withdrawn in 10 years, the NATO project would have failed. Instead, the size of the force gradually increased to more than 300,000. The U.S. military presence, albeit at a reduced level, persists to this day.
Eisenhower actually increased the linkage of America’s security to that of Washington’s European allies. His doctrine of massive retaliation made it clear that the United States would treat an attack on another NATO member as it would an attack on America. The U.S. response might include an escalation to thermonuclear war. This was the famous “Ike’s Bluff” explored by Evan Thomas in his book of that title. But, despite some criticism in the United States about the dangerous inflexibility of this policy, the NATO allies seemed relieved. Eisenhower’s stance reduced the danger that Washington would separate American and European security interests. Tight linkage, the Europeans assumed, also would inhibit the Soviet Union from seeking to split the alliance.
Conversely, John F. Kennedy’s subsequent adoption of a “flexible response” policy, intended to replace massive retaliation, worried NATO capitals. As Christopher Layne of Texas A&M University documents in his seminal book, The Peace of Illusions, Europe’s NATO members sought multiple assurances of security solidarity. U.S. officials nearly always obliged. Kennedy’s secretary of defense, Robert S. McNamara, was categorical on the point: “The United States is prepared to respond immediately with nuclear weapons to the use of nuclear weapons against one or more members of the Alliance. The United States is also prepared to counter with nuclear weapons any Soviet conventional attack so strong that it cannot be dealt with by conventional means.”
This outlook prevailed throughout the Cold War. During the 1970s, the Nixon and Ford administrations vehemently opposed the Mansfield Amendment, sponsored by Democratic Senate Majority Leader Mike Mansfield, which would have reduced, but not eliminated, U.S. ground forces in Europe and elsewhere in the world. President Nixon’s National Security Advisor Henry Kissinger (later secretary of state) fought the proposed reductions ferociously. In his memoirs, he stated that the U.S. deployments, especially in Europe, needed to be enhanced, not diminished. “At heart, Mansfield was an isolationist,” Kissinger declared, invoking the canard typically employed by status quo advocates to dismiss calls for a more flexible and restrained foreign policy. The Mansfield proposal was dangerous, Kissinger argued, because “our allies would lose heart” over fears that Washington’s security commitment to them was no longer reliable.
The reassurances went beyond formal statements and resistance to objectionable legislative measures. U.S. conventional deployments remained robust, and Washington escalated matters during the late 1970s and early 1980s. That’s when NATO leaders decided to deploy U.S. medium-range, nuclear-capable missiles in Europe as a way of enhancing the alliance’s deterrent and strengthening the linkage between NATO’s conventional forces and U.S. intercontinental strategic systems. Washington’s options if a war broke out thus narrowed further.
U.S. leaders even undercut their own demands for greater burden sharing as other NATO members maintained low defense outlays while enjoying the free ride provided by America. This was not new. As early as December 1953, Secretary of State John Foster Dulles asserted bluntly that the United States might initiate an “agonizing reappraisal” of its defense commitment to Europe if the allies didn’t make more serious efforts to build military capabilities.
More than six decades later, Defense Secretary Chuck Hagel voiced hints of a limit to Washington’s patience. Hagel admonished the Europeans during a February 2014 meeting of NATO defense ministers, declaring: “Our alliance can endure only as long as we are willing to fight for it, and invest in it.” This was “mandatory—not elective,” he added.
NATO’s European members routinely dismissed such warnings as lacking credibility. Alan Tonelson, former associate editor at Foreign Policy, aptly identified the inherent futility of Washington’s burden-sharing approach:
U.S. leaders never gave the Europeans sufficient incentive to assume greater relative military responsibilities. The incentive was lacking, in turn, because Washington never believed it could afford to walk away from NATO or even reduce its role, if the allies stood firm. Worse, U.S. leaders repeatedly telegraphed that message to the Europeans—often in the midst of burden-sharing controversies.
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The perceived need among U.S leaders to limit Washington’s policy options was not confined to NATO. There also was a proliferation of U.S.-led security alliances around the world, including bilateral mutual defense treaties with Japan (1951), South Korea (1953), and Nationalist China (1954). Although these treaties carefully avoided language obligating America to go to war if the security partner were attacked, multiple statements from a succession of U.S. administrations indicated that such an official limitation was not to be taken seriously. Moreover, U.S. warships and aircraft in the extreme western Pacific and tripwire U. S. ground forces in Japan and South Korea made it clear that the United States would be involved in any war that might break out. Once again, American leaders chose to constrain the republic’s policy options.
It appeared for a time that Donald Trump might alter the traditional U.S. approach to allies and adopt a more conditional, flexible strategy. In his most definitive foreign policy speech during the 2016 presidential campaign, Trump asserted: “Our allies are not paying their fair share” of the collective-defense effort. He added: “The countries we are defending must pay for the cost of this defense, and if not, the U.S. must be prepared to let these countries defend themselves.” This language strongly suggested that the security commitment was not absolute.
In July 2016, Trump indicated that the question of America’s defense of the Baltic republics depended on whether they had fulfilled their alliance obligations. Asked during an interview with the New York Times whether NATO countries, including Lithuania, Latvia, and Estonia, could count on the United States to extend aid if Russia attacked, Trump answered: “Have they fulfilled their obligations to us? If they fulfill their obligations to us, the answer is yes.” Implicitly, if they had not fulfilled their obligations, the answer would be “no.”
Reporters quickly noted that such comments sent “a chill through Europe.” Both domestic and foreign supporters of tight linkage between the security interests of the two regions reacted with anger and apprehension. South Carolina’s Republican Senator Lindsey Graham argued, “Statements like these make the world more dangerous and the United States less safe. I can only imagine how our allies in NATO, particularly the Baltic states, must feel.” He added he felt certain that Russian President Vladimir Putin was “a very happy man.” Graham said Trump was “essentially telling the Russians and other bad actors that the United States is not fully committed to supporting the NATO alliance.” NATO Secretary General Jens Stoltenberg added, “Solidarity among Allies is a key value for NATO. This is good for European security and good for U.S. security.”
Nevertheless, Trump’s aloofness toward NATO’s Article 5 surfaced occasionally even after his inauguration. Foreign Policy noted that following a public session at the NATO summit on May 25, “in which Trump refused to endorse NATO’s collective defense clause and famously shoved the Montenegrin leader out of the way,” leaders of the 29-member alliance seemed “appalled.”
Nor did Trump confine his skepticism to the NATO commitment. Various statements hinted at a willingness to consider fundamental changes in other aspects of U.S. security strategy. Candidate Trump said he wouldn’t necessarily object if Japan and South Korea decided to build their own nuclear deterrents. He also displayed a palpable lack of confidence that the defense obligations in the defense treaty with Japan were truly “mutual.” During a campaign rally in Des Moines, Iowa, he vented his frustration. “You know we have a treaty with Japan where if Japan is attacked, we have to use the full force and might of the United States,” Trump said. “If we’re attacked, Japan doesn’t have to do anything. They can sit home and watch Sony television, OK?”
But once in office, Trump and his appointees moved gradually to reassure both European and East Asian allies that the U.S. security commitment remained firm. Vice President Mike Pence made that point categorically: “Make no mistake, our commitment is unwavering. We will meet our obligations to our people to provide for the collective defense of all of our allies…an attack on one of us is an attack on all of us.” Likewise, U.S. military leaders in East Asia confirmed that Washington’s extended deterrence commitment to Japan and South Korea would be guaranteed “through all categories of military capabilities including conventional and nuclear weapons.”
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The United States needs a more flexible security strategy. U.S. leaders should embrace the Robert Taft policy of the free hand. A wise superpower would keep its options open as much as possible. It makes no sense to undertake commitments or deploy U.S. military forces in a manner that could trap the United States in wars unrelated to vital American interests. Yet that is what U.S. policymakers have done for decades and continue to do.
NATO’s Article 5 is dangerously close to an automatic commitment to go to war if a member state becomes embroiled in any armed conflict. But determining whether an ally is victim or aggressor can be extremely difficult. The Baltic republics, for example, have rather tense relations with their Russian neighbor. Two of them also have large Russian minorities that would likely look to Moscow for protection if discrimination against them becomes blatant and onerous. If fighting broke out, it would be extremely difficult to refrain from coming to the aid of a treaty ally, even if a Baltic government provoked the incident.
There are other worrisome possibilities as well. Consider the November 2015 incident in which Turkey shot down a Russian jet fighter that had strayed into Turkish airspace for a mere 17 seconds. Moscow’s response to that outrageous action was restrained and peaceful. But what would Washington’s options have been if Putin had ordered airstrikes against the offending Turkish missile batteries? One could argue that Turkey was not the victim of aggression but had committed aggression. Yet U.S. leaders would have been under tremendous pressure to honor the security pledge to a treaty member.
Continuing the forward deployment of military forces intensifies the risks that rigid U.S. security commitments already entail. It is imprudent to station troops, tanks, warplanes, and missiles in NATO countries near the Russian frontier. Even a minor incident could instantly engulf those units in combat, effectively foreclosing Washington’s policy options. Indeed, that is why those members want the U.S. deployments. Daniel Szeligowski, senior research fellow at the Polish Institute for International Affairs, emphasized, “From the Polish perspective, the deployment of U.S. troops to Poland and Baltic states means a real deterrence since it increases the probability of the U.S. forces engagement in case of potential aggression from Russia.”
For the United States to severely limit its policy options regarding war and peace was dubious enough when the stakes involved strategically important allies. But NATO’s membership expansion since the mid-1990s greatly magnifies the folly. America is now incurring the same grievous risks to defend tiny, strategically marginal “allies” (actually, dependents) such as Slovenia, Montenegro, and the Baltic republics.
The same effect occurs with the stationing of U.S. forces near the Demilitarized Zone between North and South Korea. The DMZ would be the flashpoint in any conflict that erupted between the two Korean states, and American military personnel would be drawn into the fighting from day one.
Denying U.S. leaders the element of choice about participating in a war that involved U.S. allies was the whole point of deploying such tripwire forces during the Cold War. Such inflexibility was unwise even when the United States faced an existential threat to its security. It is incredible folly to perpetuate those self-imposed shackles when no such threat exists. America needs a policy for the 21st century that maximizes the republic’s options while reducing both its obligations and attendant risks.
Ted Galen Carpenter, a senior fellow in defense and foreign policy studies at the Cato Institute, is the author of 10 books, the contributing editor of 10 books, and the author of more than 700 articles and policy studies on international affairs.