BUSH AND BLAIR, two leaders who have in common monosyllabic names beginning with “B” and spines of steel, are linked forever in history by their decision to rid the world of Saddam Hussein. In the last two days, the one has addressed his nation, the other his parliament about the coming war. For all the overlap in the thrust and content of their speeches, however, the president and the prime minister differed interestingly in the justifications they offered for intervening in Iraq.

First, Bush and Blair differed in the way they grounded the legitimacy of using force to dislodge Saddam’s regime. Bush was the more radical. While he cited last fall’s U.N. Security Council resolution 1441–as well as its predecessors from the 1990s, resolutions 678 and 687, both still in effect, and both authorizing “the United States and our allies to use force in ridding Iraq of weapons of mass destruction”–he traced the legitimacy of his action beyond them, to its very root, asserting: “The United States of America has the sovereign authority to use force in assuring its own national security. That duty falls to me as commander in chief by the oath I have sworn, by the oath I will keep.”