I think the Bush Doctrine is a self-fulfiling prophecy, at least with regard to Iraq.

The current justification for war on Iraq runs something like this: Saddam Hussein is manufacturing weapons of mass destruction, which he may use against the US. The probability of such a strike is great enough that we need to move first. But if a nation has the right to attack preemptively if it sees another nation as likely to attack it, then Saddam has a right to nuke the US. Indeed, he probably has more right than we have to attack him. The likelihood of a Iraqi strike on the US is still debated (despite the administration's best efforts to pin September 11 on Saddam), and even if there is an attack it would be several years away, most likely. But American military action against Iraq is pretty much guaranteed to happen, by early 2003 at the latest. Bush is essentially giving Saddam the ideological justification to attack the US in order to establish the preconditions for a US attack on Iraq.