this is another hard shift to the right by trudeau.
historically, canada has always rejected unilateral military action. ambrose is wrong in her statements - the conservatives supported multilateralism under diefenbaker, clark and mulroney.
what trudeau is doing here is signalling that the liberal party has adopted stephen harper's position on the marginalization of the united nations in favour of american unilateralism - and i fully condemn his language in the strongest terms possible.
justin trudeau is not a liberal, and perhaps never was. he is a conservative, and he is recreating the liberal party in the image of stephen harper.
https://www.thestar.com/news/canada/2017/04/07/canada-not-part-of-us-strike-on-syria-but-backs-efforts-to-stop-atrocities.html