Winston Churchill, master of eloquent bellicosity, is also remembered for saying that "'Jaw, jaw' is better than 'war, war.'" As a general matter, who could disagree? If conflicts can be settled by the arts of politics and diplomacy, they should be. But are there situations when "jaw, jaw" makes things more dangerous than the plausible threat of "war, war"? Can the soft power of "jaw, jaw" change minds bent on wickedness, absent the mind-concentrating possibility of the use of hard power ?

The classic cautionary tale here involves Neville Chamberlain and Adolf Hitler. Prime Minister Chamberlain's "jaw, jaw" with Hitler at the 1938 Munich conference wrote a death sentence for independent Czechoslovakia; when Chamberlain returned to London to proclaim "peace with honor" to the cheering throng, Sir Orme Sargent, a senior Foreign Office official, observed acidly, "You might think that we had won a major victory instead of betraying a minor country." That betrayal -- which was rooted in Chamberlain's vane conviction that he could talk Hitler into reason and moderation -- helped unleash the dogs of war, on very unfavorable terms for the defenders of civilization.

The Kennedy-Khrushchev summit of 1961 was another example of "jaw, jaw" making things worse. By Kennedy's own (off-the-record) testimony, the Soviet dictator ran roughshod over him. Coming shortly after the Bay of Pigs fiasco in Cuba, the Vienna summit left Kennedy worried that Khrushchev judged him a weakling -- a premonition that proved warranted a year later when the Soviet Union began installing nuclear-armed ballistic missiles in Cuba, dramatically escalating the Cold War. The net result of a failed "jaw, jaw" between JFK and "Mr. K"? The Cuban Missile Crisis, and a world teetering on the brink of "one minute to midnight"(as Michael Dobbs' new book on the drama of October 1962 puts it.)

"Jaw, jaw" was unavailing in the 1990s as Yugoslavia came apart at the seams; "jaw, jaw" has arguably made matters worse with North Korea (now a nuclear power), Zimbabwe, Sudan, and Burma. On the other hand, "jaw, jaw" prevented a bloody little war between Argentina and Chile in the late 1970s; "jaw, jaw" broke the political-military logjam between Egypt and Israel and led to the first Arab-Israeli peace treaty; and "jaw, jaw" may just have taken hold in the embryonic political institutions of Iraq, making something approaching responsible and responsive government possible there.

In the presidential campaign, the question of whether "jaw, jaw" is always better than "war, war" will likely focus on Iran. For six years, the world has known about Iran's secret nuclear programs. American and European diplomacy has failed to get Iran to come clean on what it's really up. The U.N. has proven less-than-useless; the organizations's chief nuclear inspector, Mohamed El Baradei, is usually dismissive of western security concerns about Iran's nuclear program. Last December's U.S. National Intelligence Estimate, which claimed that Iran had stopped pursuing the weaponization of nuclear technology shortly after Saddam Hussein fell, is of cold comfort when you realize that building the bomb itself is relatively easy; what the Iranians have been concentrating on in recent years is hard part -- creating sufficient quantities of weapons-grade plutonium.