'The 13th-century theologian set out the rules for a just war – and an intervention in Syria would fall short of them, says Jacob Rees-Mogg
"It is notable that the means of involvement in this war is by sending arms, not troops. If the war were wholly just and the intention rightful then it ought to follow that a just ruler would want to be directly involved in securing peace. Yet desire to do so by proxy indicates either an uncertainty of purpose, or a lower value being placed on Syrian lives." '
I would argue the opposite, that it is by receiving arms rather than foreign intervention that Syrians have the best prospect of keeping their future in their own hands.
I did study Aquinas for a week once.