Washington (CNN) It ought to be nothing but good news that two nations who could obliterate the globe with their nuclear weapons are meeting to mend their dangerously spiraling relations .

"We can all get along. It's going to be great. The world has to start getting along," President Donald Trump, said, touting his just announced summit with Russian President Vladimir Putin during a visit to Wisconsin Thursday.

But when Trump and Putin sit down in Helsinki the spotlight will be on everything but their crucial talks on North Korea, Syria, Iran and fraying disarmament treaties and fears of a new arms race.

Trump's own shock-and-awe diplomacy, his odd habit of cozying up to the Russian leader, his recent attacks on America's closest allies while favoring US enemies and the morass in American politics over a Kremlin election meddling operation will make their debut stand-alone encounter rich with intrigue and uncertainty.

Trump whipped up a new storm over Russia Thursday with a tweet that gave credence to Russia's denial that it had intervened in the 2016 White House race and defied US intelligence assessments, only minutes before the summit was announced.

"Russia continues to say they had nothing to do with Meddling in our Election!" Trump tweeted.

Russia continues to say they had nothing to do with Meddling in our Election! Where is the DNC Server, and why didn't Shady James Comey and the now disgraced FBI agents take and closely examine it? Why isn't Hillary/Russia being looked at? So many questions, so much corruption! — Donald J. Trump (@realDonaldTrump) June 28, 2018

In normal times, the talks in Helsinki, a city that resonates with the echoes of Cold War diplomacy, would not be seen as controversial but overdue, since Trump has been in office for 17 months and broader US-Russia relations are at their lowest ebb since the fall of the Soviet Union. The two nations have huge issues to discuss and disagreements to defuse.

As a spokesman for Finland's President Sauli Niinisto put it: "Even small steps in reducing tensions would be in everybody's interest."

But Trump's refusal to ever criticize Putin, his incessant attacks on the institutions of the post-World War II international liberal order, his habit of repeating Kremlin talking points and his difficult relationships with Western leaders who see Russia as a threat, mean his motives are constantly questioned when it comes to relations with Moscow.

And Putin's aggressive attempts to recreate the glory of Moscow's Cold War-era power, Moscow's annexation of Crimea and incursion into eastern Ukraine and a biological weapons attack on a former Russian spy and his daughter in Britain have seen him ostracized in Europe.

In fact, some critics wonder why Trump, who is nominally the leader of the West, should be offering Putin the legitimacy of a meeting that will transfix the world -- let alone the warm embrace that he often unfolds when he meets the Russian strongman.

National security adviser John Bolton -- a Russia hawk -- acknowledged the political overhang of the summit after meeting Putin in Moscow. But he said it was vital that it went ahead.

"The President determined that despite the political noise in the US, that direct communication between him and President Putin was in the interest of the US, in the interests of Russia and in the interests of peace and security around the world," Bolton said.

'NATO worse than NAFTA'

Anxiety among US allies about Trump's approach to Putin was only exacerbated by the disastrous G7 in Canada this month when the President showed up late, left early and lambasted traditional American allies and seemed far more interested in his looming summit with North Korean leader Kim Jong Un in Singapore.

History could repeat itself at the NATO summit in Brussels and during Trump's visit to Britain which precede the Putin summit. The fear in Europe is that Trump, who is already blasting allies in the Western alliance, could try to fluff up his own strongman credentials before meeting the Russian leader.

One Western diplomatic source, speaking before Thursday's announcement said "ideally" Trump would meet Putin before NATO: "Then you don't have the G7/Singapore dynamic."

But seeking a silver lining, the source added: "If it's after, it gives allies a chance to lay out the stakes, so you can cut it either way."

Trump exacerbated concerns with his tweet on election meddling Thursday. AXIOS, meanwhile, reported that Trump slammed NATO as worse than NAFTA, the North American trade pact he sees as a plot to rip off the US at the G7.

On Wednesday night he lashed out at the European Union, undermining another pillar of the Western alliance -- furthering another Russian foreign policy goal -- saying it was set up to drain America's "piggy bank."

Just weeks ago, he called for Russia's re-entry into the G7 without consulting fellow leaders and blamed former President Barack Obama for not stopping Putin's annexation of Crimea.

Often, Trump has given the impression that he sees America's allies as a greater threat to US national security than Russia.

All of this, along with Trump's demonstrated capacity to surprise allies, appease autocrats and make concessions to wily interlocuters, is why the Trump-Putin summit worries US friends in Europe and Trump's critics at home.

If the main takeaway from his trip is more snarling body language between Western leaders and a cozy encounter with Putin, the West could be further damaged.

One downside of the troublesome atmospheric hangover from the G7 summit is that it could obscure Trump's justified complaints that many European nations are not doing enough to finance NATO's common defense burden. It's a critique he shared with his predecessors as president -- though no US leader has expressed it in such stark terms such as when he went to NATO last year and blasted American allies.

Bolton said Trump would use the summit to raise Russian election meddling, which US intelligence agencies assess evolved into an effort to help Trump and is the focus of Special Counsel Robert Mueller's investigation.

The White House points to sanctions imposed by the administration, the sale of offensive weapons to Ukraine and the expulsion of Russian spies to argue that no President has been tougher on Russia than Trump. But Trump has a habit of ignoring or surprising his own advisers, so their assurances should be taken with a pinch of salt.

After meeting Kim for instance, the President blindsided his team by announcing a halt to US military exercises with South Korea. He earlier ignored advice by aides not to congratulate Putin on his election win in March.

Any President can use his authority to shape US foreign policy as he wishes and make spur of the moment calls. But Trump's often impulsive behavior and long record of wanting to please strongmen leaders means that when he does it he faces extra scrutiny. And his interventions, like Thursday's tweets, often cloud laudable goals of his administration's strategy.

Critical issues at the summit

The administration will sell the Helsinki meeting as a chance to pursue common interests as the President seeks to negotiate nuclear disarmament on the Korean peninsula and tries to get Moscow's assurances that forces of its ally, President Bashar al-Assad will not target US-backed rebels in Syria, as part of his plan for getting US troops home.

Matthew Rojansky, who heads the Kennan Institute at the Wilson Center said a summit could be useful in reviving necessary but dormant working level contacts between Russia and the United States.

"These range from our officials at mid- and senior levels dealing with nuclear arms control and WMD non-proliferation issues to important conflict prevention and escalation prevention contacts in theaters like the Baltic region and the eastern Mediterranean," he said.

"(It is) hard to prejudge outcomes because exactly what has been missing is the clarity and depth of understanding one another's interests that can only come through direct dialogue, even, perhaps especially, in the context of a conflict," Rojansky said.

While the Trump-Putin meeting will be closely watched by NATO members, its most fervent observers might be in Ukraine.

Andriy Parubiy, the chairman of parliament in Kiev, said in Washington Thursday that he had confidence in the Trump administration's commitment to the territorial integrity of Ukraine, even though the President has recently played down the Crimea issue.

But he delivered a warning that a soft touch would not work with the Russian leader.

"The language of strength and the language of force is what Putin understands best," Parubiy said. "He should understand that the President of the United States will never give in on such fundamental issues such as freedom and territorial integrity."