Apropos of the recent announcement of Tim Kaine as Hillary's VP, here's an excerpt of a transcript from an April 2016 Senate hearing in which the Senator from Virginia is questioning the Defense Secretary on the legality of operations within Syria:
Drop the mic."I am correct, am I not, that Syria has not invited us to conduct military operation within the nation of Syria?" Kaine asked Defense Secretary Ash Carter.
"You are correct," Carter responded. "But we do have lawyers."
[source]