The Clinton campaign today deployed the former commander of the International Security Assistance Force and U.S. forces in Afghanistan to rip Donald Trump’s assessment of the Mosul campaign as ignorant of military strategy.

“The attack on Mosul is turning out to be a total disaster. We gave them months of notice. U.S. is looking so dumb,” Trump tweeted just days into the multi-front push on ISIS’ Iraq stronghold led by Iraqi and Peshmerga forces.

The former dean of the Army War College, retired Army Col. Jeff McCausland, told the New York Times that the Republican nominee’s comments show “Trump doesn’t know a damn thing about military strategy.”

Trump then told ABC’s George Stephanopoulos that “you can tell your military expert that I’ll sit down and I’ll teach him a couple of things.”

“I’ve been hearing about Mosul now for three months. ‘We’re going to attack. We’re going to attack.’ Meaning Iraq’s going to attack but with us. OK? We’re going to attack. Why do they have to talk about it?” he said.

“Element of surprise. One of the reasons they wanted Mosul, they wanted to get ISIS leaders who they thought were, you know, in Mosul. Those people have all left. As soon as they heard they’re going to be attacked, they left,” Trump added. “The resistance is much greater now because they knew about the attack. Why can’t they win first and talk later?”

McCausland fired back in a statement: “I can’t wait to sit down with Mr. Trump and hear what he has to teach me about military strategy. I’m happy to compare my record of over 45 years working in national security affairs with his any time.”

The colonel, who commanded a battalion during the Gulf War, added that “it’s impossible to mask the fact that you’re hiding thousands of troops in the desert outside Mosul as you prepare for the attack and secure bases in the area for logistical support.”

“To use historical comparisons that Mr. Trump likes so much, by the spring of 1944, the Germans knew we were going to come back and liberate France. Exactly when and where were questions of operations tactics. The Germans fortified the beaches and Rommel may have been operationally surprised, but he was hardly strategically surprised,” McCausland continued. “Mr. Trump has repeatedly stated his admiration for General George Patton, but Patton’s job prior to the Normandy invasion was to lead a ‘shadow army’ in Great Britain to deceive the Germans as to when the attack would occur. This was to assist operations and tactics. In the Far East, the Japanese knew by spring 1945 that we were going to attack Okinawa and Iwo Jima. They fortified the islands in many ways, like ISIS has done in Mosul. But they knew we were coming.”

On a conference call arranged by the Clinton campaign today, retired Marine Corps Gen. John Allen, who served as deputy commander of U.S. Central Command before leading coalition forces in Afghanistan, told reporters it “brings me no joy to have to hold this call” but he “felt compelled” by Trump’s Mosul comments. “I’ve agonized over a lot of the rhetoric I’ve heard of late.”

Allen charged that Trump’s comments undercut the operation to liberate Mosul from the “oppressive boot” of ISIS and violate the “unwritten standard” of those in politics “to always support our troops in combat.”

“However he feels personally about this operation, he should be encouraging efforts publicly rather than disparaging them,” Allen added, stressing that Mosul is a “hard fight” against a “suicidal enemy” using human shields in a dense urban environment of a million people.

Trump’s idea of “some kind of sneak attack,” the general said, reveals the candidate’s “lack of understanding about military operations.”

Allen noted that as far as deception operations “we’ve been doing this all along at the tactical level … his comments really have no credibility and they shake the confidence of our forces and confidence of our allies.”

As of this writing, the Iraqi army reported being fewer than 3 miles from entering the eastern neighborhoods of Mosul.

Also on the call was Khizr Khan, the father of slain Army Capt. Humayun Khan, who recently became publicly involved again in the Clinton campaign. The Khans had chosen not to do more politicking after their well-known appearance at the Democratic National Convention in July.

Khan told reporters he was “saddened” to hear Trump’s “remarks about our military leadership — their service and their leadership has made this country great.”

Khan said his family didn’t want to be involved in politics but Trump’s rhetoric including “hatred toward Muslims and Latinos has forced us to take a stand.”

“Donald Trump, your practice of division and hatred is unacceptable to America” and “not according to American values that we know,” Khan continued.

He called Trump “temperamentally, emotionally, mentally incapable in every way” to be commander in chief.

Trump brought up Mosul again today at a campaign rally in Springfield, Ohio.

“And unlike what they’ve done in Mosul, which is turning out to be very difficult, we’re not giving three and four months notice. We’re coming in. We’re coming in. You think General George Patton would say, ‘We’re coming in in three or four months, get ready’? What a bunch. They’re throwing people off buildings, hanging their victims from meat hooks. They’re hanging their victims from meat hooks,” Trump said.

Eleven days into the ground offensive — which includes more than 50,000 Iraqi soldiers, 40,000 Peshmerga, several hundred U.S. support troops and nearly 15,000 paramilitary troops from militias such as the Christian Nineveh Plain Protection Units and Yazidi Sinjar Resistance — about 100 towns outside Mosul have been taken back from ISIS, which leaves their former haunts heavily booby trapped.

Several dozen Iraqi and Peshmerga troops have been killed, as well as one U.S. sailor: Chief Petty Officer Jason C. Finan, 34, of Anaheim, Calif., who was killed Oct. 20 by an improvised explosive device blast. He was assigned to Explosive Ordnance Disposal Mobile Unit Three.

The U.S. and Iraq say several hundred ISIS fighters have been killed thus far.