President Obama’s two former Defense secretaries, Bob Gates and Leon Panetta, on Tuesday criticized his handling of the Syria crisis.

The former Pentagon chiefs said they would not have sought congressional approval to strike Syria after leader Bashar Assad used chemical weapons, crossing Obama’s “red line.”

Obama made a last-second decision to consult lawmakers and then asked congressional leaders to postpone a vote in favor of a diplomatic solution after widespread backlash on Capitol Hill.

Panetta, who also served as Obama’s CIA director, said the president undermined U.S. credibility by not following through with a strike against Assad.

“When the president of the United States draws a red line, the credibility of this country is dependent on him backing up his word,” Panetta told the audience at an event at Southern Methodist University.

Gates went even one step further than Panetta with his criticism, telling the Dallas audience that Obama’s promise to only use limited military force was not a coherent strategy.

“My bottom line is that I believe that to blow a bunch of stuff up over a couple days, to underscore or validate a point or a principle, is not a strategy,” Gates said. “If we launch a military attack, in the eyes of a lot of people, we become the villain instead of Assad.

“Haven’t Iraq, Afghanistan and Libya taught us something about the unintended consequences of military action once it’s launched?” Gates added.

The New York Times first reported the former defense secretaries' remarks.

Obama has defended his handling of Syria, accusing his critics of focusing too much on style points rather than actual policy.

“Folks here in Washington like to grade on style,” Obama told ABC earlier this week. “Had we rolled out something that was very smooth and disciplined and linear, they would have graded it well, even if it was a disastrous policy.”

Secretary of State John Kerry last week negotiated a deal with Russia that would call on Assad’s regime to turn over its stockpile of chemical weapons to the international community.

Lawmakers on Capitol Hill, though, have expressed skepticism about the deal, and the White House has threatened to punish Assad if he does not follow through.