If you disagree with the rationale which led to the Iraq war, then you should not vote Conservative.
If you disagree with the rationale which led to the Afghan war, then you shouldn't vote Conservative or Liberal.
That just leaves the NDP or the Greens.
Personally, I agree with the Afghan war, but now I favor negotiating a truce with the Taliban as long as they refuse to allie themselves with anyone allegedly involved in 9/11 and don't interfere with western attempts to bring these people to justice. Canada should even fund Taliban efforts to build mosques, schools, hospitals and other projects of mutual interest and encourage them to seek power by democratic means.
Regarding Iraq: Lying to justify an unprovoked war of aggression against the Iraqi people was a war crime and the people responible should be brought before the International Court of Justice and tried for war crimes and crimes against humanity. Harper supported this war crime. If he had involved Canada in that war, I'd be in favor of putting him before the ICJ too. Fortunately for him and Canada, he was just an opposition leader at the time.