For one thing, I doubt keeping soldiers in Iraq is actually going to ward of terrorism in the US. If anything they may hate us more because we're over there. Come on, there really isn't any way to physically fight terrorism. Your best bet is to raise people's standard of living, so they are not so desperate that they are willing to die for their cause.
As for higher taxes, if you want things you have to pay for them. You want good roads, it costs money. You want decent schools you have to pay for it and pay the teacher's well enough that they don't leave. You want health care for everyone, someone has to pay for it. This nation is already insanely in debt. Do we really want to add to that debt by lowering taxes. Are taxes really that bad. I agree the tax system needs some serious work. I also know that national debt probably seems like it doesn't really matter to most people, but if the people we borrowed all this money from decide they want it back, we would be in very serious trouble. Do we really want that kind of power in other people's hands?