To alter the question slightly, it is possible that Canada's biggest challenge will be to resist engagement should the current "cold war" between theUnited States, Israel and Iran turn hot. The US-led wars in Iraq and Afghanistan both failed; (fortunately, we were involved in only one of these). Canada has nothing to prove militarily. Our government is not facing an election, so has nothing to prove on that front either.
Given that an attack on Teheran would likely ignite the entire Middle East, with international repercussions; and given the uncertain realignments of the Arab Spring movements, including growing Palestinian diplomatic strength, neither engagement nor hostile sabre-rattling are useful policy options for Canada. Canada should seize the opportunity to refurbish its tarnished image by actively promoting diplomacy and dialogue, including standing behind renewed peace talks between Israel and Palestine. The smallest gains would significantly reduce tensions throughout the region.