Comander in Chief forum
Republican presidential candidate Donald Trump gushes about Russian President Vladimir Putin during the forum held by NBCReuters/Mike Segar

Republican presidential candidate Donald Trump expressed a startling point of view during a televised forum on national security: Russian President Vladimir Putin is a far better leader than US President Obama. He also reiterated an old opinion that rape of women is to be expected in the military when the genders mix.

He defended a 2013 tweet he wrote noting that there had been "26,000 unreported sexual assaults in the military," adding: "What did these geniuses expect when they put men and women together?"

"It is a correct tweet," he said on the NBC Commander-in-Chief forum in which he answered questions from members of the military. "There are many people that think that's absolutely correct."

He said that didn't mean, however, that women shouldn't serve in the military, and vowed more aggressive prosecution of rapists.

As for Putin, Trump said he is a "far more" capable leader than Obama, adding at one point that if Putin "says great things about me, I'm going to say great things about him." (Putin has been quoted as calling Trump "brilliant," which the Russian president has denied saying.)

"The man has very strong control over a country," Trump said of Putin. "Now, it's a very different system and I don't happen to like the system, but certainly in that system, he's been a leader. Far more than our president has been a leader."

Trump added: "I think I would have a very, very good relationship with Putin. I think I would have a very, very good relationship with Russia."

He also slammed the American military as an "embarrassment" and its generals so weak that they have essentially been "reduced to rubble." Trump also refused to reveal his "secret" plan to defeat Isis.

Asked about his past claim that he knew more about Isis than American generals, Trump said he would replace high-ranking military officers because of poor performance in recent years before consulting them on a final course of action.

"Well, they'll probably be different generals, to be honest with you," Trump said. "I mean, I'm looking at the generals." He insisted that World War Two General George Patton was "spinning in his grave" over the US military's failure to quickly defeat Isis.

The forum featured both Trump and Hillary Clinton in a kind of dry run for the presidential debates. Trump, as usual, was the more explosive of the two. Clinton was on the ropes defending her controversial decision to keep emails while she was secretary of state on a personal server.

"How can you expect those such as myself who were and are trusted with America's most sensitive information to have any confidence in your leadership as president when you clearly corrupted our national security?" asked John Lester, who flew surveillance aircraft in Operation Desert Storm.

Clinton noted – and an FBI investigation has backed her up – that emails on her personal server were not marked as classified. She said she took great care to use a separate process for classified information. "I did exactly what I should have done," she said.

The FBI recently released two key documents related to Clinton emails – agents' three-hour interview with Clinton and a summary of the FBI's complete findings in the case, in which the agency concluded there were no law broken.

"At the end of the day, the case itself was not a cliff-hanger; despite all the chest-beating by people no longer in government, there really wasn't a prosecutable case," FBI director James Comey said in a new memo about how the agency handled the issue.

House Democrats have just released correspondence between Clinton and her predecessor Colin Powell, who said he indicated that he used a similar process, NBC reported.

"What I did was have a personal computer that was hooked up to a private phone line (sounds ancient)," Powell wrote to Clinton. "So I could communicate with a wide range of friends directly without it going through the State Department servers. I even used it to do business with some foreign leaders and some of the senior folks in the Department on their personal email accounts."

Clinton vowed that defeating Isis was her top counter-terrorism priority, but pledged not to any ground send troops beyond the special forces and trainers already there. "We are not putting ground troops into Iraq ever again. And we're not putting ground troops into Syria," she said. "We're going to defeat Isis without committing American ground troops."

Clinton reiterated her often-repeated observation that Trump's temperament is too unstable to be trusted with the nation's nuclear weapons.

In the hours following the forum, moderator Matt Lauer came under stinging criticism for how he handled questioning. He often allowed Trump to talk over him and let the candidate dodge questions, noted the New York Times – while Lauer often cut off Clinton. At one point, Trump insisted he was "totally" against the war in Iraq, which is not the case, yet his statement was not challenged by Lauer.