Americas problems in Afghanistan and Iraq may have one positive effect: They will cause the U.S. public to withhold support for future military interventions that are not absolutely necessary for U.S. security. Thats exactly what has happened in the past and theres no reason to believe the current failed adventures will be different.
In the Korean War, for example, after back and forth offensives, the front stabilized at the 38th parallel, where the conflict had begun. With casualties mounting and no clear-cut victory in sight, the war lost much of its support. President Harry Truman was so unpopular by this time he decided not to seek re-election. During the subsequent eight years of the Eisenhower administration, the war-weary United States directly intervened militarily just once, in Lebanon in 1958.
Only after this respite was the country ready to elect another hawkish president: John F. Kennedy, an ardent Cold Warrior. The anti-communist Kennedy supported a reckless attempt to eliminate Castro in 1961, the so-called Bay of Pigs invasion, which helped set the stage for the 1962 Cuban Missile Crisis. Kennedy also dramatically increased the number of U.S. advisors in Vietnam, setting another stage.
After President Johnson escalated the Vietnam War and President Nixon prolonged it, the public got fed up again and pressured Washington to end the war without victory. Like Truman, LBJ was forced to the political sidelines.
During the post-Vietnam administrations of Gerald Ford and Jimmy Carterlasting six-and-a-half yearswar weariness again reduced the number of military interventions. Once again, however, the restraint only lasted so long, with Carters successor, Ronald Reagan, intervening in Libya, Grenada, and Lebanon, where the results were disastrous. This was followed by another hiatus, broken by George H.W. Bushs 1989 invasion of Panama.
War weariness can even result after U.S. victories. In 1846, during the Mexican War, Generals Winfield Scott and Zachary Taylor won great victories against Mexican armies. Yet, even after Mexico City was taken, the war dragged on and the public became restless.
The Spanish American War in 1898 also provides parallels to the current conflicts. After the initial taking of Cuba and the smashing of the Spanish fleet by Admiral Dewey in Manila, the United States refused to grant the Philippines its independence. The U.S. military then had to wage a brutal counterinsurgency war, which killed 200,000 Filipinos and resulted in an anti-colonialist backlash in the United States. This unpleasant experience made subsequent Presidents Teddy Roosevelt, previously a hawk, and William Howard Taft chary of colonialism and direct foreign intervention.
The United States fought no major wars again until World War I.
Despite the U.S. victory in the Great War, the carnage appalled America, resulting in more than 20 years of reduced interventionism during the Harding, Coolidge, and Hoover years and the first two terms of Franklin D. Roosevelt. Then the United States was attacked at Pearl Harbor.
Though U.S. casualties were higher in World War II than World War I, the Second World War didnt produce the usual fatigue. The different outcome resulted from the United States clearly being attacked first and the complete defeat of diabolical despotic regimes: Nazi Germany, Italy, and Imperial Japan. The collapse of the fourth totalitarian regime of the 20th century, the Soviet Union, magnified U.S. hubris.
With no nuclear superpower rival with which to contend, the administrations of George H.W. Bush, Bill Clinton, and George W. Bush went into overdrive, expanding U.S. alliances and commitments, acquiring new military bases around the world, and flexing Americas military muscle where it was not really necessary.
Now, U.S. politicians and the public are beginning to realize that the greatest military in history may not be able to defeat a bunch of rag-tag and loosely organized guerillas and militias in Iraq, and the Taliban in Afghanistan.
The good news is that these twin failures, however tragic and painful, will likely usher in a new period of U.S. military restraint, the policy championed by Americas founders. The bad news is that proponents of non-interventionism will only have a limited amount of time before the public forgets the pain of unnecessary wars and Americas foreign policy elites begin rattling their sabers again.