Washington (CNN) President Donald Trump's stunning decision to meet Kim Jong Un sets up the prospect of the most mind-boggling diplomatic summit in modern history.

Trump, a reality star turned convention busting President, has dubbed Kim "Little Rocket Man" and threatened to rain fire and fury over North Korea, raising fears of a devastating war across the world's last Cold War frontier.

Kim, a portly 30-something whose state media recently blasted Trump as a "lunatic mean old trickster and human reject" presides over a prison state, purges his foes and has vowed to obliterate the US in a nuclear cloud.

In the short term, a meeting could defuse the spiraling tensions between the US and North Korea that have raised fears the two nations are on an accelerating slide to a clash that could kill millions on the Korean peninsula.

"I think this is a positive step. I think the world is breathing a sigh of relief," former CIA chief and Defense Secretary Leon Panetta told CNN, warning intricate diplomatic planning and attention to detail would be required.

Talks would represent a huge risk for Trump, who would be putting the prestige of the United States and his own credibility on the line. So far, there are few signs that he has secured significant returns to justify such a step.

For decades, the Kim dynasty has used diplomatic coercion and brinkmanship twinned with offers of talks and demands for concessions to cheat their way to a nuclear arsenal and preserve a tyrannical regime in defiance of the US.

So there's a real chance Trump could be walking into a massive trap.

Concerns about his approach will be magnified by the impulsive way he announced the breakthrough, bursting into the White House briefing room, to tell journalists to expect a major announcement.

Reflecting his craving for affirmation, the excited President told Jon Karl of ABC News, even at this early stage of the process "hopefully, you will give me credit," offering little sign he appreciates the magnitude of the task he faces.

Top officials in the Pentagon, and even in his own White House were unaware something was afoot until Trump appeared before reporters. Secretary of State Rex Tillerson, who earlier cautioned that talks with Pyongyang were a distant prospect, was thousands of miles away in Africa.

Trump's own inexperience in high stakes diplomatic negotiations increases the size of his gamble. Then again, there is no evidence that Kim has ever met another head of state.

Decades of hostility

It is impossible to overestimate the suspicion that exists between North Korea and the US, 70 years after the end of the Korean War, which never officially ended with no formal peace agreement reached.

That's why many analysts, foreign policy experts and Pentagon officials are skeptical about the meeting, if it goes ahead.

"The chasm of distrust is so great on both sides it will take extraordinary persistence to find a basis upon which both sides can work together," said Scott Snyder, of the Council on Foreign Relations.

"There is no record of shared accomplishments, we're starting from scratch in an attempt to overcome over 70 years of animosity."

The President has so far shown little sign that his vaunted deal making skills have transferred from the real estate business to politics or diplomacy -- yet he is taking on one of the most intractable disputes of the last century.

His aides quickly started presenting the initiative as the "Art of the (nuclear) deal."

"President Trump has made his reputation on making deals," said one senior administration official. "(Kim) is the one person who is able to make decisions under their authoritarian -- or totalitarian system."

The talks could be a huge political payoff for a President who mired scandal, is viewed with venom around much of the world and is at risk of becoming a one-term President unless he can rescue his sagging popularity.

In the short term, Thursday's news will distract from the mushrooming scandal of Trump's alleged affair with porn star Stormy Daniels and the relentless march of special counsel Robert Mueller deep into the White House.

If it goes ahead, Trump's meeting with Kim would go down in history alongside such diplomatic coups as Richard Nixon's courting of Mao Zedong's China.

If it succeeds in significantly lowering tensions it could be worth it in itself and ultimately, a peaceful resolution of the crisis would rate almost as highly as a historic political achievement as the US triumph over the Soviet Union.

Such stakes appeal to Trump's ego, and he would relish the chance to pull off a diplomatic achievement that none of his predecessors managed.

"This is one of those moments in history when you have to throw the Hail Mary, when you have to give it a shot," said Harry Kazianis, of the Center for the National Interest.

The invitation from Kim follows a flurry of activity by the North Korean leader, including his decision to send a team to the Winter Olympics in South Korea.

It is likely a sign that the most stringent ever sanctions imposed on the North Koreans through the UN Security Council as a result of a US initiative are beginning to bite and impose severe pressure on Kim's regime.

Just by securing a meeting with Trump, Kim could achieve something North Korea has been seeking for decades -- the legitimacy of standing side-by-side with an American President on an equal footing.

A traditional approach to diplomacy would use the carrot of presidential talks to secure serious concessions, like agreements from the North Koreans to halt satellite launches and to allow inspections of its nuclear plants.

Were Trump to give away leverage of his visit for a glorified photo op and fail to secure a pledge beforehand for verifiable denuclearization by Kim, the meeting would be widely portrayed as a failure crushing to US credibility.

Kim is also playing a long game, hoping to remain in power long after Trump is gone, and after a successful period of tests of his nuclear and intercontinental ballistic missiles may now feel a long diplomatic process is in his interests.

After Pyongyang's most powerful missile test yet, in November, Kim announced that his country had "finally realized the great historic cause of completing the state nuclear force," according to state news service KCNA.

Initial indications were that Trump had agreed to a meeting without getting a tangible payoff from Kim -- and intends to handle the process himself. The South Koreans said the talks could take place as soon as May.

Trump's move recalled his gift to Israel of a huge political win by declaring Jerusalem as the Jewish state's capital and pledging to move the US embassy from Tel Aviv, without securing anything in return from the Israelis.

All Trump got for his agreement to meet Kim was a vague undertaking for denuclearization from the North Koreans and an agreement to refrain from future missile and nuclear testing -- with no guarantees.

Thursday's announcement also represents a diplomatic triumph for the South Korean government of Moon Jae-in, which Trump recently lashed for appeasing the North. In effect, Seoul has now roped the President into a diplomatic process, forestalling for now, the risk of a pre-emptive US strike.

Moon's government, elected on a platform of engagement with North Korea, has scored the political victory of delivering on that promise. Seoul has also regained control of the geopolitical dynamics surrounding the tensions on the Korean peninsula, neutralizing Trump's veiled threats of pre-emptive strikes by coopting him and allowing him to claim credit for potential talks.

But it will take time and work before the US and North Korea can get to the point of negotiating, analysts and officials say. And history indicates that the chances of success may be slim.

"The record of accomplishments as a result of direct talks suggests that if those talks lead to direct negotiations, it will be a very difficult path," Snyder told CNN.

"Given the alternative, it's a path that's logical to pursue, but we just can't put great hope in it."