In Britain, the ruling Labor Party has fallen on hard times. Boris Johnson, a quirky Conservative, has ousted Ken Livingstone, a quirky Laborite, as mayor of London. Around the nation, the Labor Party fared badly in local council elections held on May 1. Prime Minister Gordon Brown is being second-guessed for not calling a national election soon after succeeding Tony Blair last year, and he is generally being skewered as a bungler in the London tabloids.

But as this happened, Mr. Brown held a one-hour meeting in London with Gen. David Petraeus, commander of American forces in Iraq, and with Ryan Crocker, U.S. ambassador to Iraq. The meeting (which followed meetings with British defense officials) ended with an announcement that Mr. Brown would delay his previous plan to reduce British forces in Iraq to 2,500 this spring. Britain will maintain 4,000 troops at Basra Airport “for the long term.”

Prime Minister Brown’s reversal is based on his understanding that Iraq is at a crucial juncture. Widely perceived as less keen on the war from the beginning than Mr. Blair, he has demonstrated why Britain remains America’s closest ally. He obviously would have preferred to bring British forces home. But facts are stubborn things, and like so many of his predecessors, Mr. Brown had the intelligence, and with it the necessary fortitude, to see them as they are.

Today, the war in Iraq is even less popular in Britain than it is in the United States. Mr. Brown’s decision cannot help him politically. All the more reason it should command respect.