Watch: Political Scientist Dominic Tierney Says Syria Conflict is a "War for Credibility"

"The entire case for war in Syria really hinges on this idea that chemical weapons are uniquely evil," said Dominic Tierney, Associate Professor of Political Science, on MSNBC's The Last Word with Lawrence O'Donnell (above), "But the distinction between chemical weapons and conventional weapons is fairly arbitrary."

In an appearance on the Melissa Harris-Perry show (below), Tierney added that "This is a war for credibility. America's credibility, Obama's personal credibility, the Democratic party's credibility."

An expert in international conflict, Tierney also discussed the situation in Syria on CNN Newsroom. "The whole case for war is based on the idea that chemical weapons are uniquely evil, a unique threat," he said. "But I think the distinction between chemical weapons and conventional weapons is arbitrary, really. It is not clear that chemical weapons are more brutal than conventional weapons like high explosives are less brutal. After all, conventional weapons have killed 100,000 Syrians. Chemical weapons killed 1,000."

Tierney is a senior fellow at the Foreign Policy Research Institute and a correspondent at The Atlantic. He is the author of three books, How We Fight: Crusades, Quagmires, and the American Way of War (Little, Brown, & Co., 2010), FDR and the Spanish Civil War: Neutrality and Commitment in the Struggle that Divided America (Duke University Press, 2007), and Failing to Win: Perceptions of Victory and Defeat in International Politics (Harvard University Press, 2006).

Tierney joined Swarthmore's faculty in 2005 after completing his Ph.D. in international politics at Oxford University and serving as a post-doctoral fellow at the Mershon Center at Ohio State University and the Olin Institute at Harvard University. In 2008-2009, he was a research fellow at Harvard's John F. Kennedy School of Government.