Retired Marine General James N. Mattis gave an insightful talk to a packed crowd at the Aspen Security Forum on Saturday.

The four-star general, who recently retired after leading U.S. Central Command, which is responsible for Iraq and Afghanistan (among others), spoke at length with CNN's Wolf Blitzer on Syria, Iran, Israel, and Egypt.

He offered commentary on U.S. foreign and military policy, what is happening in the Middle East, and what he sees going forward.

On what's happening now in Syria:

Mattis made clear that without the support of the Iranians, Syria's Bashar al-Assad "would have been overrun" by rebel forces. The reason Iran props up the regime, Mattis reasoned — is that if Assad falls, it would be Iran's biggest political setback in 25 years.

He also expressed dismay over Iran's free usage of Iraqi airspace to shuttle arms into the country, saying "when we pulled out of Iraq, we certainly didn't expect" anything like that.

On whether the U.S. should go into Syria:

Mattis continued to harp on having a political end state and clear goals before any military action — whether that be boots on the ground or no-fly zone — or else he said, "you invade a country, pull down a statue, then say 'now what do we do?'"

The general told Blitzer the military "is not worn out" and can carry out any mission, but "we should not fight wars without a clearly defined end state ... when you go to war, it can't be a half-step" — meaning, you have to be fully committed to winning.

On going into Iraq:

When asked whether it was "worth it" to go into Iraq, Mattis was reluctant to directly answer. "There's a big 'if'," he said, on whether Iraq continues with their democracy and flourishes. If that happens, Mattis reasoned, "then yes."

On Iran's development of nuclear weapons:

Mattis believes Iran is roughly one year from having a nuclear weapon, and doesn't believe military action could solve the issue. A strike would only delay it, but he has "no doubt" Israel would strike if they had a bomb.

"The military can buy our diplomats some time," Mattis said, but it cannot solve the problem alone.

On whether Egypt was a 'coup':

Mattis would not directly answer whether or not Egypt was a coup, but said that what happened in Egypt is "a setback for democracy." He offered no love for the Muslim Brotherhood, who he said "brought on [their] own problems."

On strategy and sequestration:

Although he didn't directly address having a timeline to leave (as is the case of a 2014 Afghanistan pullout), Mattis said that you "don't ever tell the adversary in advance what you're not going to do."

He's now retired, but as a servicemember on active duty, he could only offer advice to policymakers, not orders. "I don't write policy for my government," Mattis said. " ... I just carry out the last 600 meters of my President's policy."

Mattis also warned that Admirals and Generals need to "stop sucking their thumbs and whining about sequestration, telling the world we're weak" because it sends a signal to nations such as Iran and North Korea, and they may start to believe it.

On his and the rest of the military's service:

"I was a Marine for 41 years and it wasn't long enough," Mattis said. He told the crowd they shouldn't thank him for his service, because "we enjoy putting on that uniform."

"The ferocity and the ethical performance of our troops," he said, " ... sends a signal that free men and women can fight."

There's much more in the full talk below: