(CNN) Even by the combustible standards of Donald Trump , the spectacle set to unfold around his presidency in time zones 12 hours apart in the next few days could defy description.

On one side of the planet, Michael Cohen, the President's former personal lawyer, is expected to dish dirt in a congressional hearing on Trump's turbulent personal and business affairs that are becoming an increasing legal and political threat.

On the other side in Vietnam, Trump will be pursuing a Nobel Peace Prize, convening a second summit and media extravaganza with North Korean tyrant Kim Jong Un that will take place despite a lack of genuine progress since their first encounter.

Trump is giving the talks top billing. He said at the White House on Sunday night that he has a "very, very good relationship" with Kim.

"We see eye to eye, I believe," Trump said.

Yet Cohen's appearance, if it brings significant revelations and congressional fireworks, is likely to complicate and detract from Trump's efforts to orchestrate an international peace pageant at the summit in Hanoi, and could also inflict serious political damage on the President even as he is out of the country.

In another sign of the controversy perpetually swirling around this White House, House Democrats will meanwhile vote on Tuesday on a resolution to terminate what they say is Trump's "lawless" state of emergency declared to finance his border wall. The move will impose new pressure on Senate Republicans and could eventually draw a presidential veto.

And hovering over everything will be the expectation that once the President is back home, special counsel Robert Mueller will soon file a report that could have grave implications for the Trump presidency.

How the Cohen show may upstage the Kim sit-down

Perhaps only in the age of Trump could a nuclear summit between a President and the tyrant leader of a hermit nation with which the US has been technically at war for nearly 70 years be the second biggest news story of the week.

Cohen's testimony before the House Oversight Committee on Wednesday has the potential to be a historic moment in the Trump administration and to thicken the cloud of sleaze that has engulfed his White House.

According to the Democratic leadership of the committee, Cohen, who once served as Trump's fixer, will discuss "debts and payments relating to efforts to influence the 2016 election." That subject will include payments made by Cohen to buy the silence of two women who claimed they had affairs with the President, which Trump has denied multiple times.

Cohen, who once guarded the secrets of the Trump empire, is also expected to testify about "potentially fraudulent or inappropriate practices by the Trump Foundation" — the subject of a civil lawsuit brought by the New York Attorney General's Office.

On Friday, the New York Times reported that Cohen had given information about possible irregularities in Trump's family businesses to prosecutors in New York in a move that reflects the President's growing legal peril.

What Cohen may say

Democrats on the committee may also ask whether Trump directed Cohen to lie to Congress about a plan to build a Trump Tower in Moscow, one of the crimes for which the attorney will shortly go to prison.

It is not clear whether the Department of Justice or the special counsel have directed Cohen not to address any specific questions given that they could be germane to Mueller's continuing investigation.

But House Oversight Committee Chairman Elijah Cummings, D-Maryland, said Cohen will talk about "public efforts by the President and his attorney to intimidate Mr. Cohen or others not to testify" after the lawyer canceled an earlier appearance saying he feared for his family's safety.

Intimidating witnesses, as Cohen claims the President did, and trying to get a witness to lie to Congress, are offenses that could potentially be investigated in any impeachment proceedings initiated by House Democrats against Trump.

"Looking forward to the #American people hearing my story in my voice! #truth," Cohen wrote on Twitter last week.

Trump insisted that he has no concerns about what may unfold in room 2154 of the Rayburn House Office Building on Wednesday, in a somewhat oblique comment on Friday.

"No, no, no," Trump said. "'Lawyer/client,' but, you know, he's taking his own chances."

The White House and Republicans will assail Cohen's testimony by pointing out that he is already an admitted liar and that everything he says should be dismissed. So the question of whether he can corroborate his claims about Trump will be critical.

"No one should be scared of the truth, but everyone should be scared when the deck is stacked in favor of a liar," Ohio Rep. Jim Jordan, the top Republican on the Oversight Committee said in a statement last week.

Extreme pressure on Trump for results

Cohen's appearance will take place in the middle of Trump's visit to Hanoi where he will meet Kim for private one-on-one talks, and negotiations with delegations.

That means that any bombshells in Washington could disrupt Trump's efforts to grab center stage for the meeting and force him to address any such issues if he talks to reporters.

That the summit itself is going ahead at all is controversial since Trump has arguably not extracted any concrete progress since last year's Singapore summit, despite making several significant concessions.

The White House insists that a lack of missile or nuclear tests by the isolated state and the return of the remains of 55 US war dead from the Korean War are significant steps. Trump has claimed hyperbolically that his predecessor Barack Obama was close to "a big war" with North Korea — an argument that the former President's national security team has refuted.

Ahead of the summit, White House press secretary Sarah Sanders downplayed expectations and accused the media of using the summit to attack the President.

"He's had great success here in the fact that they were even able to sit down at the table. The fact that he's able to do it again is in itself a big success," she said.

It's a fair point that talking to the North Koreans and reducing tensions is a worthy goal and makes Americans safer. And if Trump convinces Kim to verifiably give up nuclear weapons, he would deserve the praise that history would heap on him for an achievement no other President managed.

But there is extreme pressure on Trump to produce something tangible from the summit after Kim agreed at the first to "work toward complete denuclearization" of the Korean peninsula but has so far failed to follow through.

Director of National Intelligence Dan Coats angered Trump last month by saying in congressional testimony that US spy agencies assess that North Korea will seek to retain its weapons of mass destruction and is unlikely to completely give up nuclear weapons and production facilities because its leaders view the arsenal as "critical to regime survival."

Pompeo on the spot

After the Singapore summit last year, where he became the first US President to meet a North Korean leader, Trump tweeted the false claim that "There is no longer a Nuclear Threat from North Korea."

Just landed - a long trip, but everybody can now feel much safer than the day I took office. There is no longer a Nuclear Threat from North Korea. Meeting with Kim Jong Un was an interesting and very positive experience. North Korea has great potential for the future! — Donald J. Trump (@realDonaldTrump) June 13, 2018

But so far there is not even a common definition agreed by each side about the core issue.

A senior White House official told reporters last week that one of the goals of the summit would be to develop a "shared understanding of what denuclearization means."

In an exchange with CNN's Jake Tapper on "State of the Union" on Sunday, Secretary of State Mike Pompeo sought to reconcile the President's misleading rhetoric with the reality of North Korean intransigence.

"Do you think North Korea remains a nuclear threat?" Tapper asked.

"Yes," Pompeo replied, promoting Tapper to point out: "The president said he doesn't."

"That's not what he said," Pompeo said, before Tapper quoted Trump's tweet.

"What he said was that the efforts that had been made in Singapore, this commitment that Chairman Kim, may have substantially taken down the risk to the American people."

Tapper replied ... "OK. I mean, that's just a direct quote, but I want to move on."

There is palpable anxiety in the foreign policy community and even inside the White House that Trump's desperation for a win in Hanoi could lead him to make substantial concessions that could further weaken US leverage.

That temptation could be all the greater if Cohen steals the show.

In Singapore, Trump shocked US allies and his own officials by freezing US-South Korea military exercises in what was seen as a big win for Kim — but which has not unlocked key concessions from Pyongyang.

This time there are signs that Washington is prepared to water down one of its previous demands that the North provide a full inventory of its nuclear and missile programs ahead of any new US concessions.

Some experts believe that Trump could try to smoke Kim out this time by offering to exchange liaison offices in the two nation's capitals, or by agreeing to a peace declaration to formally end the Korean War.

The latter move would satisfy Trump's need for an eye-catching PR coup after his open campaigning for a Nobel Peace Prize , but it would have huge implications since it would weaken the case for US troops staying in South Korea.

US officials have insisted that the US garrison is not on the table in the summit.