It looks like the beginning of a long, hot summer in Washington. There is an unofficial deadline of July 31 for the Haitian military junta to step down or face a U.S.-led invasion. And the clock is now ticking down to a different kind of deadline for North Korea -- but one that could also lead to U.S. military intervention.That, at least, is the conventional wisdom in an American capital where the old Clinton campaign slogan of "It's the economy, stupid" is being replaced by a new mantra -- "It's credibility, stupid."After a series of foreign policy defeats and humiliations, the Clinton administration has lost much of that automatic deference to America as the last superpower that they inherited from George Bush.The withdrawal from Somalia after the U.S. Rangers were ambushed, and the retreat of U.S. troops aboard the naval ship Harlan County as an armed mob jeered from the dock, and the dithering over Bosnia, have all combined to make the prospect of American military power much less menacing. People are just not afraid of Bill Clinton.In the 12 years of the Reagan-Bush presidencies, the world grew accustomed to a robust American diplomacy of invasion. It may have built a wary respect for American power and beefed up presidential credibility, but it was also the geopolitical equivalent of casual sex -- never staying around to commit the United States to a lasting relationship. Afghanistan has resorted to tribal strife. Saddam Hussein remains defiantly in power. Panama is still a major cocaine entrep™t.But having grown accustomed to an America which was promiscuous in its deployments of power, the foreign policy establishment in Washington and the allies who have learned to expect firm U.S. leadership are all fretting at Bill Clinton's apparent timidity.And the expectations of military action are high and rising. A series of military exercises, described as "routine training" by the Pentagon, have over the past two months seen the rehearsal of amphibious beach and helicopter landings by U.S. troops, together with small contingents of troops from allied Caribbean countries. These open military preparations have escalated in step with Clinton's strengthening rhetoric.There is little relish for an invasion of Haiti inside the White House, except for the crucial political consideration that such a display of Clinton's readiness to use force will do wonders for his credibility. "We may be driven to invade Haiti just so we don't have to attack North Korea," was the way one National Security Council aide put it, not entirely in jest.But the really important decision on the Korean crisis, which will be taken in the next few weeks, will be whether or not to start reinforcing the 36,000 U.S. troops already there. The deployment of extra troops and the shipment of more ammunition stocks and extra armor, which will take weeks to arrive, is the signal that North Korea is watching for as they try to assess Clinton's resolve.Will the only draft-dodger ever elected to the White House have the nerve to attack Haiti and also send reinforcements and prepare for war in Korea? The fact that we can put it like this betrays one dismal fact. The decision is less about Haiti or Korea than about making the world frightened of America again. If it comes, it will be the war of Bill Clinton's nerve.