After last month's flap about which foreign leaders support him, you'd think John Kerry would jump at the chance to get a few words of support from George W. Bush's closest ally. But when British Prime Minister Tony Blair tried to meet the Democratic presidential candidate this week, Kerry said he was just too busy.

Both sides insisted they wanted to meet the other and blamed scheduling difficulties. But the cool response from the Kerry campaign is an unusual twist in what should be an easy relationship. Both leaders are liberals at home and internationalists abroad. Both were lawyers in their early careers and both play the guitar in their downtime. Both have even shared an adviser in Bob Shrum, Kerry's media guru who helped Blair's team during its 2001 re-election.

So why the scheduling problems? "With the prime minister, every minute is accounted for and I'm sure that is absolutely the same when you are running for president of the United States," said one British official. But the problems seem easy to solve. Blair flies from his vacation in Bermuda to New York on Thursday--the same day Kerry leaves Manhattan, after a campaign stop with Hillary Clinton the day before.

Blair built a close personal and political bond with Bill Clinton, modeling his New Labour party on Clinton's New Democrats. The two men mused so much on the future of their parties that British officials openly fretted when George W. Bush moved into the White House. Three years later, the tables have turned. Now Blair is so closely tied to Bush and the war in Iraq that Kerry's aides tread warily. Some question how much help Blair could provide when their Democratic base loathes Bush and questions the war. There is also concern that a joint appearance will simply revive the controversy about Kerry's unnamed foreign supporters. Meanwhile, in London, Blair is reported to have told his ministers to avoid showing support for Kerry by not traveling to the Democratic National Convention in Boston this summer--a favorite boondoggle for Blair's party.

Both Kerry and Blair might be wise to be wary. Meddling in foreign elections can often backfire. Bush's aides tried to steer German voters away from re-electing Gerhard Schroder during the run-up to the war in Iraq, accusing the German leader of poisoning relations with the United States. It took months to repair the diplomatic damage. And few in Blair's party have forgotten how a Conservative prime minister--John Major--tried and failed to help the first President Bush win re-election in 1992. Major's officials searched British records to dig for dirt on Clinton's years at Oxford University, prompting one senior Labour politician to condemn the operation as "very disturbing" and "completely unacceptable." His name: Tony Blair.