You can't understand today's Iraq debate without understanding Karl Rove's view of the nation's political crossroads and the longer-term struggle between Democrats and Republicans to achieve a new governing majority. If you're convinced that Iraq is purely about national security, read no further. If you want to understand the full picture, let's go to the heart of darkness.
The defining feature of American politics in recent years has been the remarkable parity between the two parties. You can't get closer than the presidential tie in 2000, not to mention the narrow majorities in Congress.
Yet periods of closely divided power are unusual in America. Our system of government has generally favored the creation of effective majorities. Think of FDR and the New Deal coalition, which lasted from the 1930s until it gave way in the late 1960s under the strains of Vietnam and the backlash against civil rights.
Ronald Reagan presided over a period of conservative power from 1980 to 1992. Most analysts view eras of closely divided power as periods in which one system of effective majority has broken down and the next system of effective majority has not yet come into being.
In this view, the 1990s look transitional: Reagan's majority broke down, but Bill Clinton couldn't get Democrats to the promised land.
In their important new book, The Emerging Democratic Majority, John Judis and Ruy Teixeira argue that long-term trends - in particular, the rise of suburban professional women, Latinos, and a white working class that feels economically insecure - favor the Democrats.
Many Republicans think these trends favor Democrats, too. That's why George W. Bush, learning the lesson of Newt Gingrich, has always pretended to have a "compassionate" agenda.
But Republican political consultants privately know the surest way to stem the Democratic drift is for the war on terror to become the master narrative of American politics.
In their view, one of two things will happen in the next few years.
In the first scenario, national security (and internal security) become the dominant issues in our politics, and Democrats, trusted less on these matters, revert to their minority status of the 1970s and 1980s.
The other scenario is that the public tires of the struggle, or terrorism remains (thankfully) rare, or there's a decisive "victory" somehow. In this case, Republican weaknesses on domestic problems come back into focus. These weaknesses were a problem in the 1990s but not fatal, in GOP eyes, because of the public's qualms about Bill Clinton's character. But under a less-vulnerable new leader, in this scenario, Democrats should be able to re-emerge as a "third way" majority party.
As one conservative thinker said to me, "If the war on terrorism is not a big deal, it's hard to see the conservatives ever coming back." On the other hand, if the war on terrorism remains a big deal, the Democrats may split.
One benefit of invading Iraq that conservatives speculate openly about is that it will tear the Democratic Party down the middle, as did Vietnam. A peace candidate in New Hampshire in 2004 is the new Republican fantasy.
It turns out affirmative action and immigration were just the warm-up. Now war is the GOP's ultimate wedge issue.
I'm not saying this is all that motivates the White House. But I have no doubt it is part of what motivates some powerful people near the President.
Serious Republican thinkers believe the only way for their party to achieve a governing majority is for the theme of war to be dominant. This is a fact, and whatever else you may think of it, it's a little scary.