Neo-Con Vs. Patriot
The first time Secretary of Defense James Mattis met with National Security Advisor John Bolton he told him “I’ve heard that you’re actually the devil incarnate and I wanted to meet you.”
Now it is being reported they are clashing on how to proceed in Syria, with Mattis preferring the conservative approach and Bolton wanting to take his usual aggressive approach.
It's not that general Mattis is necessarily opposed to the strikes (it's his field of expertise), but they’re worried about the very real possibility of blowback against their troops. They’re almost certainly arguing for much more limited strikes that would be mostly cleared with the Russians in advance.
While National Security Advisor Bolton is most certainly pushing his neo-con agenda, trying to convince the president to ignore the general’s fear and simply assume the Russians will go back on their word.
Bolton is a war hawk who is always pushing for war. He would welcome Russia hitting back so he can escalate to an even larger war for Israel and Saudi Arabia, both of which benefit from Assad's removal.
The only question that remains is which side will the president go toward, that of the Secretary of Defense or that of his National Security Advisor. Neither of which acknowledges Russia's claim that the chemical attack was a complete hoax perpetrated by the western backed rebels.