After my recent travels through Tennessee, Georgia and the Carolinas to assess the impact of Barack Obama's candidacy on the old Confederacy, my NEWSWEEK colleague John Barry sent me a note about his days reporting on the presidential campaign of George Wallace, the former governor of Alabama, back in 1968. Wallace's race-baiting populism eventually was sanitized and absorbed into the Republican Party's successful "Southern strategy," but Wallace himself was much rougher and more honest in his opinions than his mainstream emulators. He knew that what attracted Southern voters to him was not so much what he stood for, but the many things he stood against. "You got to understand," he told Barry one day as he gazed at the statue of a Confederate soldier in his home town, "All we've had is defiance."

That's it, I thought. That is what Yale professor C. Vann Woodward was saying when he wrote in the 1960s that Southerners were different from other Americans precisely because a century before, in the 1860s, they became the only white people in the United States to be conquered and occupied. All they had left was their attachment to defiance, which lingered for generations and remains among some Southerners to this day.

Defiance has ever been the sustenance of the weak and defeated, the overpowered, the demeaned and the enslaved. It is the essence of "Forget, hell!" but also of "We Shall Overcome." It is what a Roman Catholic academic in Northern Ireland called "f--- you rage and resentment." It is at the core of the Palestinian cause, and of Iraqi resentment and resistance. Whether noble and courageous or just bloody-minded and intransigent, the instinct for defiance is a defining, driving force in national and international affairs. But it is not one that Washington has ever understood very well, and that has meant, quite literally, a world of trouble.

As we've seen in the Caucasus over the last week, the desire to appear defiant can lead to enormous miscalculations by a leader who thinks Washington will back his play. Georgian President Mikheil Saakashvili seems to have believed he could rely on solid Bush administration support when he attacked Russian forces in the breakaway province of South Ossetia. After all, the Bush administration had sent more than 1,000 troops to Georgia for a joint exercise just last month. It talked up Georgian membership in NATO despite deep misgivings by many European allies. Privately it warned Saakashvili not to provoke the Russians, but he seems to have missed that point, deciding to defy the odds, as well as Moscow, and launch his offensive.

A more thoughtful man might have recalled the way Hungarians fighting the Soviets, Argentines fighting the Brits, Shiites and Kurds fighting Saddam Hussein in the 1990s thought they could depend on Washington to come to their rescue, only to be deceived and then destroyed. But when you're caught up in the romantic cause of defying the enemy you sometimes start defying reason, as well.

In the case of Georgia, the Bush administration seems to be confused and posturing--upping the ante with humanitarian aid but clearly leery of military confrontation. Having done so much to sap American economic and military strength and diminish its own diplomatic credibility over the last seven years, the White House now finds itself peculiarly vulnerable to the one-upmanship of its defiance-driven friends, who cannot win wars by themselves, but can start fights that Washington may feel it has to finish. Today that risk is front and center in the Caucasus. Tomorrow the same sort of situation could be created in the Middle East, where a defiant Iran is squared off against a defiant Israel. If the Israelis decide it's time to start bombing Iran's nuclear installations, whether or not the U.S. is consulted beforehand, it will wind up at war.