How binding is the Popes stand on practicing Catholics
It is not binding at all.
Besides, how would he "bind" a Catholic to oppose the war?
This is a political judgment on the Pope's part, which is no more binding on Catholics than my political judgment.
I was enlightened by another Freeper today (Sabretooth) that the radical Muslims are chomping at the bit to turn this into a crusade against Christians, and a papal siding with the US might just be the trigger.
Besides, preaching peace is the Pope's job. Everybody expects it.