Retired Adm. Mike Mullen expressed deep doubts that the North Koreans can be trusted to live up to any deal. | Drew Angerer/Getty Images Former Joint Chiefs head fears Trump will lash out if North Korea summit fails

The potential for a war between the United States and North Korea will deepen if the upcoming summit between President Donald Trump and North Korean leader Kim Jong Un fails, the former chairman of the Joint Chiefs of Staff warned Tuesday.

Retired Adm. Mike Mullen told Johns Hopkins University’s School of Advanced International Studies he is “encouraged by the fact that the two leaders are going to talk" and gives Trump “a lot of credit for moving the needle on this.”


But Mullen, who served as the top military officer under former Presidents George W. Bush and Barack Obama, said he worries that Trump’s public tone on North Korea in recent months — including "casually threatening a nuclear holocaust over Twitter” — spells trouble if the summit does not succeed.

"If the talks do fall apart, the failure is likely to stir the president’s most bellicose and aggressive instincts," Mullen predicted. “Rhetorically, President Trump has already walked all the way out to the edge of the cliff. There’s not much further he can go. ... I don’t know if I can fully convey to you how shocking it is to hear the commander in chief talk about nuclear weapons with such nonchalance.”

He also expressed deep doubts that the North Koreans can be trusted to live up to any deal.

“Most of us who have spent a lifetime working on national security remain a bit skeptical," Mullen said. "We need to plan for the likelihood that even if the talks seem to be productive, the North Koreans have no intention of honoring their word.”

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Mullen also insisted there is no military solution to the standoff, even a limited attack on some of the North's military facilities — or the so-called bloody-nose attack that the White House has reportedly considered.

“It’s a strategy we’ve considered in the past as well. The problem is, in my judgment, the risk is through the roof,” Mullen said.

“We have no reason to believe Kim Jong Un will respond to a bloody nose by backing down," he said. "It is just as likely, if not more so, that we will respond by drawing blood on our side, too" — with missile strikes on South Korea “at a minimum.”

Mullen added of Kim: “Even as he seeks recognition from the United states, he is fully convinced we are on a mission to take him out.”