All along Tony Blair has been what Beaverbrook called Lloyd George, "a prime minister without a party." He never had any affinity with the Labor MPs he led, and by now he is totally at odds with them. Today, in another hallowed phrase from British political history, he increasingly looks a man in office but not in power. His domestic policies are in disarray, one poll after another shows that most British people think the Iraq war was unjustified, and the sale of honors (which I wrote about a little frivolously in Slate last month) is burgeoning into the gravest political scandal for many years.

With all of that, Blair's personal stock remains high in the United States. In some ways, from the theatrical jes' folks manner to the religious zeal, he has always been a more American than British figure. Plenty of Americans—some for a time dubbed the "Blair Democrats"—preferred the prime minister's rhetoric about the Iraq war to what they heard from their own president, and even now Blair gets something of a free pass from Americans who hate the war and damn George W. Bush to perdition.

So, it might be the moment for an Englishman opposed to the war to explain why, for some of us here, Blair comes out of Iraq not better than Bush but much worse.

There is now no great secret about how the administration took the United States to war, and none about Blair's reason for supporting Bush. As the Labor politician Aneurin Bevan would have said, why look into the crystal ball when you can read the book? British troops are in Basra because of something Blair knew and something he believed.

He knew that Washington was going to invade in any case, and he believed that "it would be more damaging to long-term world peace and security if the Americans alone defeated Saddam Hussein than if they had international support to do so." So he told one London journalist, telling another that he was worried about an American drift toward unilateralism and that his mission was to embrace Bush so as to "keep the United States in the international system."

The harder these arguments are looked at, the more curious they seem. You don't say: "My big brother is a crazy kind of guy. On Saturday night he likes to get blind drunk and drive through town at 90. It would be more damaging to peace and security if he acted alone than if he had my support, so I'll go along with him for the ride." Either Washington was doing something wise and virtuous, in which case it should have been supported for that reason, or not, in which case should have been restrained and, if necessary, opposed. As to binding the Bush administration into the international order, judge for yourself.

A sophisticated defense of Blair  has been advanced by my colleague Christopher Hitchens: Blair was the original exponent of humanitarian intervention. And yet, apart from the inconvenient fact that Blair did not propose an invasion of Iraq before it was proposed to him, there are difficulties with this.

Since World War II the United Kingdom has ceased to be a great military power, not only from inevitable decline but because the British, like other Europeans if not quite so much, chose butter against guns. To simplify the statistics, in the decade after 1945 British military spending dwarfed welfare spending; now it's the other way around. There are today fewer armed men under the crown than there were in the 1770s when we were fighting the rebellious Americans.Or look at another telling comparison:In the campaign in northwestern Europe of 1944-45 the ratio of American to British dead was around 5-to-2, in Iraq in 2003-06 it has been 22-to-1.

A British prime minister with such scant military resources is thus in a most invidious position if he urges the United States to undertake operations of which his own country is incapable. And Blair has learned the hard way that a meager single division of British troops gives him very little real influence in the White House or the Pentagon.

To see the other problem you must read what Blair actually said in his earlier days. The key text his defenders flourish is his April 1999 speech in Chicago, in which he discussed the new global situation and argued that the rules of absolute state sovereignty that had prevailed since the Peace of Westphalia in 1648 could no longer be final. A very good speech it was—not surprisingly, since most of it was written by Sir Lawrence Freedman, the eminent military historian and theorist. The crucial passage addressed the potential need for military action in the Balkans or the Middle East or wherever it might be. Before deciding "when and whether to intervene," Blair said "I think we need to bear in mind five major considerations."

"First, are we sure of our case? ... Second, have we exhausted all diplomatic options? ... Third, on the basis of a practical assessment of the situation, are there military operations we can sensibly and prudently undertake? Fourth, are we prepared for the long term? In the past we talked too much of exit strategies. But having made a commitment we cannot simply walk away once the fight is over ... And finally, do we have national interests involved?"

All of that seems quite lucid and coherent. And seven years later, Blair deserves to be asked: Were all of those conditions met in the case of Iraq? Was any?

But the deepest flaw of all in Blair's position was pointed out by Robin Cook three years ago. Cook was Blair's first foreign secretary from 1997 to 2001, when he was demoted, just possibly because his absolute loyalty was already suspect, and in the spring of 2003 he became the one important member of Blair's government to resign in protest at the war, not long before his sudden and untimely death. In his resignation speech in parliament, Cookmade the lethal, obvious point that the invasion would not be taking place if Al Gore were in the White House. Blair's "crazy big brother" position boils down to saying, absurdly,"My policy is to stand by the American adminstration at all times. I loyally and uncritically supported the decision of President Bush to invade Iraq, just as I would have loyally and uncritically supported the decision of President Gore not to invade Iraq."

When the warbegan Blair won rapturous American applause by saying that "however tough" it might be, he would fight alongside the United States with "no grandstanding, no offering implausible and impractical advice from the touchline. ... We will stay with you to the last." Three years later, those Americans who continue to admire Blair should consider where that boyish loyalty took their country. 

Just possibly, Blair was the one man who could have prevented, or at least delayed, the invasion. But even if he was going to support it, he could at least have asked a few direct questions of White House and Pentagon. "We may have enough troops for the formal military conquest, but are we sure that we have enough to secure the country after that? And do we have a considered political plan for Iraq once Saddam has been deposed?" Perhaps a little advice from the touchline might not have gone amiss.