It never rains but it pours. If there is one thing Gordon Brown will not miss when he goes to Washington in a few days’ time for his first visit to the White House since taking over as prime minister, it is the British weather.

After years of drought, the country is enjoying, if that is the right word, its wettest summer for decades, and parts of the south of England are presently under water. Hurricane Katrina it is not.

Nobody has actually been drowned in the latest floods, though a few died last month in the north, and even the worst hit towns, built in floodplains of the Rivers Thames and Severn, have not been submerged, as New Orleans was by the Mississippi.

One of them, Gloucester, has always been vulnerable, as the old nursery rhyme reminds us. “Dr. Foster went to Gloucester in a shower of rain. He stood in a puddle right up to his middle, and never went there again.” And summer storms have been around even longer — witness music like Vivaldi’s “Four Seasons” or art like Giorgione’s “La Tempesta.”

By the standards of a pampered press however, this July counts as the “worst peacetime disaster in living memory.” It is, of course, being blamed on global warming by the vociferous lobby that now makes a fat living out of such alarmism.

The Tory leader, David Cameron made a global fool of himself this week when he swanned off to Rwanda to demonstrate that he cares about African poverty and climate change, only to be grilled by the local press about why he wasn’t back home among his electors in Oxfordshire, who are among the worst hit by the deluge.

The new prime minister is proving to be unexpectedly popular. Last week he won two by-elections, partly because Mr. Cameron put his own name on the ballot papers. Britons don’t like presidential politics and refused to vote for “David Cameron’s Conservatives.” Mr. Brown easily held on to both seats in Parliament, one of which had been left vacant by his predecessor.

By chance, Tony Blair is back in the limelight this week on his first outing as Middle East envoy. If his mandate obliges him to pursue the chimera of a “peace process” leading to a “two state solution,” he will do more harm than good.

What he will not be allowed to do, alas, is to tell the Palestinians the unpalatable truth: that their misery is mostly their own fault, that the Arab world has done less than nothing to alleviate it, and that they were never better off than when they were living under Israeli rule. Since the 1994 Oslo accords, the fatal conceit of a Palestinian state has left the West Bank a kleptocracy and Gaza a theocracy.

Mr. Blair’s mission may be impossible, but it is not as unenviable as that of President Bush. Sometime in the next few months, he will almost certainly launch a massive assault on Iran’s nuclear facilities.

This has been clear to anybody with an ounce of strategic sense ever since it became obvious long ago that the Islamic Republic’s front man, Mahmoud Ahmadinejad, was exploiting negotiations to gain time. It is bad enough that such a volatile state as Pakistan already has its “Islamic bomb.” But the West can mitigate the danger posed by Pakistan’s nuclear weapons by helping President Musharraf to defeat his Islamist enemies.

For Mr. Bush to allow Iran to develop an “Islamist bomb” would be the worst dereliction of duty by a Western leader since Neville Chamberlain’s attempt to appease Hitler. Almost as bad, however, would be a refusal by Mr. Brown to support America’s armed forces in the formidable task of eliminating Iran’s underground installations. Asked to rule out a military solution this week, Mr. Brown pointedly refused to do so.

The Iranian operation will be at the heart of the Bush-Brown discussions. Both men know that the two-front war they are already fighting has stretched their military capabilities to the limit. In Britain’s case, indeed, the chief of staff of the armed forces, General Richard Dannatt, is apparently telling his political masters that his troops are seriously overstretched.

But the third front against Iran should, if the offensive is successfully prosecuted, help to relieve pressure on coalition forces in Iraq and Afghanistan. Iran is the major source of assistance to the Iraqi insurgents and the Taliban. The best — indeed only — response to low-intensity warfare is high-intensity warfare. A surgical strike to decapitate a regime that has been waging a proxy war against us for years would be justified under the Bush doctrine.

The third front in the war on terror will be harder to explain to the American and British peoples than the first two. That is why both leaders need to start preparing their nations now. It never rains but it pours.