I never support boycotts. Ever. I happily ate lettuce and grapes in the '70's, would have bought Krugerands in the '80's if I had had enough cash, and currently drive both a Chevy and a Ford. I don't believe in mixing politics with my duty as a consumer to maximize my own utility. If you're truly conservative, you won't either.
On the other hand, I support government actions to sanction Iran, restrict trade with Syria, etc., etc. Some things are properly done by government and government alone. I wish we could control our government and turn it to more conservative policies, but our failure to do so is political and should not interfere with our duty to watch out for number one in matters of consumption.