I don't know anything about the UKIP, but it is probably incorrect to say that the "Tea Party" opposes a missile strike.

The Tea Party is a loosely organized faction of the Republican Party. It is not a party in the sense that it runs candidates on it own or has a "spokesman" or "chairman" in any official sense. Many Congressional Republicans aligned with the Tea Party may oppose intervention but not all.

There are also Democrats who are opposed. Unusually for these days, the split is not along party lines.