Paul Bremer, who led the government in Iraq following the U.S.-led invasion, joined Martha MacCallum to discuss the options for President Obama to deal with the advance of ISIS militants toward Baghdad. Bremer argued that it was a mistake for Obama to say on Friday that he would not commit U.S. ground troops.

"I would not ever think it’s a good idea to say what you won’t do in any case. It’s not a message of strength to our friends or enemies in the region," said Bremer, adding that there is a difference between having troops on the ground and having a combat force in Iraq.

He explained that U.S. troops will have to be on the ground to identify targets for drone strikes and gather intelligence. Before U.S. troops can deploy, Bremer pointed out that the Iraqi government will have to sign a status of forces agreement.

Bremer said Obama's biggest misstep, however, was the complete withdrawal of U.S. forces from Iraq. He explained that when that happened, Iraqi Prime Minister Nuri al-Maliki installed a Shiite-dominated government and replaced many of the U.S.-trained military officers with "partisans."

Watch Bremer's full analysis above.