President Trump and Kim Jong Un abruptly ended their second summit in Hanoi, Vietnam with no deal on North Korea's nuclear program. The president said Kim wanted sanctions fully lifted in exchange for closing only some of its nuclear sites. After the talks ended, Mr. Trump said, "Sometimes you have to walk."

So who was the winner this time around?

"Really, no one. No one walked away with what they wanted," retired Gen. Vincent Brooks said Thursday on "CBS This Morning." Brooks helped coordinate the historic first summit in Singapore as the commander of U.S. Forces Korea. "South Korea didn't see the progress they hoped for, China didn't see the progress they hoped for, North Korea didn't get the relief they wanted. The United States did not get the disclosure it wanted."

But he stressed the meeting was not a diplomatic failure.

"It's another step in diplomacy. First, I'm very happy as a military former commander to see that there is diplomacy and that there's not a need to pursue a military option at the present time. That's what we were pursuing in 2017," Brooks said.

"What the U.S. got out of this is a clearer understanding of what it is that concerns Kim Jong Un the most, and that he does indeed intend to release his nuclear weapons, but he doesn't know the way to get there and doesn't have a foundation of trust."

He said the outcome is a "big setback" for Kim on the international stage. According to Brooks, it's been 450 days since the regime's last provocation. ("Yes, I'm counting. I was then, and I still am," he said.)

"It's not that [Kim] wants his nuclear weapons. He wants economic development. He now sees that he has to take a different way to get there. He gambled and missed," Brooks said.

Despite failed negotiations and broken promises in the past, Brooks said it's important to note what is different this time around with Kim.

"He's not his father or he's not his grandfather. And he's trying to deliver something that he believes they attempted and failed to do — a new relationship with the United States. Peace on the Korean Peninsula, preservation of the regime, and economic growth and development that he delivers. And so this is a different circumstance than before. He also achieved the nuclear weapons that his grandfather did not," Brooks pointed out.

Trump and Kim left without plans for a third meeting, but Brooks said he anticipates a third meeting, as well as another South Korea-North Korea meeting and China-North Korea meeting. "They will express their concerns to Kim Jong Un and maybe help to try to put him back on track, as well," Brooks said.