I hate disagreeing with Bill Scher of Liberal Oasis, but I think it would be suicidal to vote against the $25b request for Iraq and Afghanistan. First of all, the money is badly needed for body armor, etc. Second, the war in Afghanistan is underfunded as it is. Third, there's still a Homeland Defense Credibility gap to cross with swing undecided voters, and voting against this money gives all too easy a soundbite to the opposition (Tom Delay already invoked the Support Our Troops meme).
What Kerry has to do is demand more money - about $40b. Make the discrepancy large enough that it becomes a wedge between Bush and the fiscal conservatives. Kerry needs to emphasise that this war has been fought on the cheap with poor planning, and that the troops still don't have the body armor they need. Given that the Senate will grill Rumsfeld on the failures of training and discipline, Kerry's message that the troops are not being supported by the Administration will resonate.
I don't see a flaw in asking for more money - either Bush refuses, and erodes his own credibility, or concedes in which case Kerry gets the credit and Bush inherits the consequences from within the GOP.