MSNBC host Matthews: Can a Syria attack deter Iran on nukes?

Visit for breaking news, world news, and news about the economy

Matthews said if a U.S. military strike in Syria does not stop chemical or nuclear weapon use in the Middle East, another solution will be hard to find.

"If you can't say, 'If you do this we're blowing you up,'" Matthews said on "Morning Joe." "If that doesn't work, what does work? And that's the problem." 

Matthews said al-Assad's use of chemical weapons broke a global pact even WWII leaders respected.

"I don't like what I'm going to say but it's true," Matthews said. "It's been enforced around the world for decades. We don't use chemical weapons. 

"We didn't even use them in WWII," he said. "Hitler didn't even use them. We don't use chemical weapons."