(KCEN/KXAS) -- President Barack Obama made a moral argument for a targeted military strike against Syria in his presidential address Tuesday night.

He called Syrian President Bashar al-Assad's alleged chemical weapons attack on civilians "a crime against humanity and a violation of the laws of war" as well as "a danger to our security."

Reiterating his support for a strike to punish Assad, Obama insisted that no American boots would be put on the ground there.

"When dictators commit atrocities, they depend upon the world to look the other way," Obama said. "But these things happened. The facts cannot be denied. The question now is what the United States of America and the international community is prepared to do about it."

The president also said that he had asked Congress to postpone its consideration of a resolution to authorize a strike, amid a flurry of international diplomacy aimed at pushing Assad to turn over his chemical weapons arsenal.

He called such talks "encouraging" while he attributed them to the "credible threat" of U.S. action and said it was "too early to tell" if diplomacy might work