General John Allen blast Donald Trump says He has 'No Credibility'

Retired Marine Corps Gen. John Allen excoriated Republican nominee Donald Trump after the businessman called him a 'failed general' and criticized Allen's endorsement of Hillary Clinton.

"He has no credibility to criticize me or my record or anything I have done," Allen said on ABC's "This Week." "If he'd spent a minute in the deserts of Afghanistan or in the deserts of Iraq, I might listen to what he has to say."

Allen gave a full-throated endorsement of Democratic nominee Hillary Clinton in a speech at the Democratic National Convention Thursday night. He spoke flanked by more than 35 veterans.

In his speech, Allen slammed the Republican nominee without naming him: “With [Clinton] as our commander-in-chief, our international relations will not be reduced to a business transaction.”

Trump hit back in a tweet, saying Allen "failed badly in his fight against ISIS," and continued in an interview on ABC's "This Week" to criticize the retired Marine general.

“He didn’t beat ISIS. He didn’t do even well with ISIS,” the Republican nominee told ABC’s George Stephanopoulos.

Allen, a four-star general who served as commander of U.S. forces in Afghanistan, recently served as the U.S. special presidential envoy for the international coalition fighting ISIS.

Trump added more generally about the U.S. military effort against ISIS that “the generals aren’t doing so well right now,” but added that may be “Obama’s fault.”

“If you look at ISIS -- General McArthur and General Patton, they're spinning in their graves. The generals certainly aren't doing very well right now,” he said.

Allen said Trump's comments about the military are a "direct insult" to men and women currently serving in the armed forces.

"What we do have to do, George, is listen to what he's been saying about our military," Allen said. "He's called it a disaster. He says our military can't win anymore. That's a direct insult to every single man and woman who's wearing the uniform today." 

[ABC News]