I'm unconvinced. I'm as much of a deficit hawk as anyone under normal conditions, and I deplore the disconnect between the two as much as anyone. But an additional tax is never a good idea during a recession. That was the whole point of the stimulus. (One could add that it's a good reason to get us out of the war, since money spent in Afghanistan does not aid the US economy, but national security always ends up trumping economic problems.)
This does mean, though, that we should probably consider "war taxes" in future conflicts. This was (part of) how we paid for the Second World War, and World War I, and the Civil War. In fact, the first income tax was to pay for the Civil War (levied on BOTH sides). While the economics aren't in favor of it now, if we come out of recession and are still in Afghanistan, then it might be a good idea to pay off the war.
Because, honestly, paying taxes to support your country is a patriotic thing. If you enjoy the services you get (including our overly-massive military), you should be willing to pay for it. Just not in a recession.