08/24/2012 03:15 pm ET Updated Oct 24, 2012

Interest Creep, Intervention, and Military Power

American interests have long been extensive, but the number of interests justifying a military response has been on the rise. Identifying interests, threats to those interests, and counters to those threats is an important element of strategy formulation. The more interests, the greater the potential costs to defend them. Resources are finite and some interests are more important than others. As Fredrick the Great said, "to defend everything is to defend nothing." Tough choices must be made. What choices are the presidential candidates likely to make?

Mission creep is now an established part of the security lexicon. An administration may enter a local conflict with humanitarian objectives (e.g., Bush 41 and Somalia) and, having found itself in the midst of a civil war, expand the mission to peacemaking (e.g., Clinton and Somalia). Without arguing the wisdom of the original intervention and its evolution, it is a recurring pattern that shouldn't be ignored. These types of interventions can solve or exacerbate problems or result in stalemate. Regardless, they are costly.

Interest creep is another expensive phenomenon, but it requires a longer view to recognize. It is most readily apparent as a post-WWII evolution. Interests are prioritized or simply differentiated as vital or peripheral. An inability to differentiate between vital and peripheral interests, and the threats to them, is the first step to overreach and strategic exhaustion, as Eisenhower cautioned, destroying the thing he swore to defend.

To provide security, the state must assure territorial sovereignty and the lives, property, prosperity, and way of life of the American people. There is general agreement that protecting these things is a vital interest. Assuring prosperity and way of life leads quickly to ensuring the free flow of cheap Middle Eastern oil to the industrialized world and to guaranteeing freedom of the seas. And, for some, American national security is achieved by assuring global security, and defending global security becomes a vital interest. If we don't act, then our credibility as global policeman is damaged, and preserving U.S. credibility as global guarantor becomes a vital interest. And finally, some believe the way to achieve national security is to spread democracy, and that becomes a vital interest justifying war. When do these commitments become overextension?

After WWII, U.S. interests were redirected from defeating rightwing fascism to defeating leftwing communism. Two names are associated with the Cold War strategy to contain the spread of communism--George Kennan and Paul Nitze. Both served under President Truman, Kennan under Secretary of State George C. Marshall after FDR's death, and Nitze under Secretary of State Dean Acheson after Truman's election. An important way to differentiating their thinking is through another component of strategic thought, the threat equation (threat = intent X capability). Kennan, an experienced foreign service officer, focused on difficult-to-quantify Soviet intentions. Nitze, a product of the Washington bureaucracy, focused on the easier to count military capability.

Kennan's assessment was that Russia was incapable of tolerating diversity and would attempt to impose its image on the world. He believed that the Soviets had no intention of entering into a direct war with the U.S., that the long-term competition would be political warfare, and that the USSR would eventually exhaust itself. Acquisition of the A-bomb would make the Soviets more capable but not more threatening. Other capitalist democracies would share our interests, and a military balance of power based on shared interests should be sufficient. There was no need for a military buildup. Kennan considered an arms race a threat in and of itself because it harmed the economy and led to war.

Kennan defined vital interests narrowly. He was most concerned with those few countries able to wage industrial-age warfare: the U.S., Great Britain, Japan, Germany, and Russia. Preventing Germany and Japan from falling into the Soviet sphere was a vital interest. They should be rebuilt and drawn into the U.S. sphere. Kennan proposed a strongpoint defense including Germany, Japan, and the Philippines. If there was to be military confrontation, it would be over vital interests and where the U.S. was advantaged. Kennan explicitly rejected military involvement in Korea, Indochina, and Afghanistan. The U.S. was not advantaged in war on the Asian land mass, and no vital interests were at stake.

Nitze's strategy lost Kennan's emphasis on potential industrial capacity. Kennan's strongpoint defense was replaced with a perimeter defense. Defending every country on the Soviet periphery became a vital interest. Nitze defined the Cold War in military terms and an arms race rather than as a political contest. A massive military buildup was necessary to achieve a preponderance of power over the Soviet Union. Nitze's strategy required more than a tripling of the defense budget. Only a few years into the Cold War, the U.S. had quickly extended a security guarantee to Germany, Japan, Western Europe, Taiwan, South Korea, and Israel.

Democratic administrations tended strongly to Nitze's containment, arms buildup, and interventionism. Republican administrations tended strongly to Kennan's containment, arms reductions, and noninterventionism.

Truman took the U.S. into the Korean War under UN authorization but without authorization from Congress. Kennan had explicitly rejected U.S. military involvement in Korea.

Eisenhower adopted a Kennan-like strategy early in his administration (the Solarium Project) and force reductions followed. Eisenhower campaigned to end the Korean War and did. Even though the Domino Theory has its roots in an Eisenhower speech, he skillfully avoided direct involvement in Vietnam. He resolved the Suez Crisis through economic diplomacy. At the end of his administration, there were no U.S. forces committed to combat anywhere. He left office warning of excessive military spending.

Kennedy campaigned against Eisenhower's defense cuts and for an arms buildup. Kennedy adopted Nitze's version of containment and expanded the perimeter defense to an anywhere, anytime, at any cost defense. An Eisenhower speech on Indochina was generalized by others into a global Domino Theory. The notion that one more state falling to communism would inexorably lead to an insurmountable Eastern alliance that would doom capitalist democracy made the competition a matter of survival. Defending Vietnam became a vital interest. Johnson took us into the Vietnam War over a contrived incident. Expansion of the military continued.

Nixon campaigned to end the Vietnam War and, slowly and painfully, he did. He shifted emphasis from the military to the diplomatic instrument. The Nixon Doctrine put friends on notice to act more like allies than protectorates.

Carter vacillated. He entered office believing the Cold War could no longer serve as the organizing principle for U.S. foreign policy, and he adopted a human rights agenda that gave a new rationale for intervention. But after the Soviet invasion of Afghanistan, he declared "an attempt by any outside force to gain control of the Persian Gulf region would be regarded as an assault on the vital interests of the United States of America, and such an assault will be repelled by any means necessary, including military force." He then returned to the traditional Democratic position and began what would later be called the Reagan arms buildup.

The invasion of Afghanistan was the culminating point for the Soviet Union, the point at which the war was lost even though the last battles had not yet begun. They knew it; we didn't. Before deciding to invade, they concluded that they would be unable to defend their East European buffer zone. They began debating the need to abandon their efforts to spread their own political and economic system and concentrate on their own more narrowly defined interests. But it was too late. Kennan's predictions came true.

Reagan changed the pattern by adopting the Democrat's arms buildup and adopting the Republican's restrictive use of force. Bellicose rhetoric, yes, but his only offensive use of ground forces was the invasion of the tiny island nation of Grenada. Hardliners in his own party called him a pussycat. Nixon recommended an arms reduction to President-elect Reagan. Instead, Reagan's massive arms buildup took the country from leading creditor nation to leading debtor nation. The Cold War came to an end under Bush 41. Bush managed an almost 20 percent force reduction in four years while ordering short-duration, decisive interventions in Panama and Iraq.

When the Cold War ended, the Domino Theory no longer held sway. The stakes were much lower and, many thought, the threshold for intervention much higher. Perhaps a peace dividend, but no. Our interests expanded again and a security guarantee was extended into Eastern Europe and Central Asia. Containment of communism worked, now spreading democracy became the vital interest justifying war.

Sixteen years of highly interventionist post Cold War administrations followed. The administrations had different motivations, but the number of military interventions accelerated rapidly. Clinton managed an almost 19 percent force reduction in eight years while operational tempo of air forces increased 400 percent and ground forces 600 percent over Cold War levels. Force structure was flat during the Bush 43 years while protracted wars were initiated and operational tempo exceeded 1000 percent of Cold War levels. Obama has adopted a strategy reminiscent of Republican traditionalists.

That our security commitments have expanded considerably since WWII is inarguable. And, I think, it is hard to argue that we do not have global interests. But honest people can disagree over which of these interests are vital and should be defended at all costs, including war, and which are peripheral and might better be managed through diplomatic and developmental efforts. Do we respond to disruptions around the globe as problems to be solved with the military or as changes to be managed with diplomacy? Perhaps it's time, as a country, that we step back and have that debate, or insist that the presidential candidates have that debate. We can't afford not to.