But the trip comes amidst revived attention to Saudi Arabia's perceived role in the September 11 attacks and tensions between Washington and Riyadh over Iran, while domestic E.U. concerns distract European leaders.
And then there's America's own domestic diversion: the acrimonious presidential race battle back home, which foreign allies are monitoring intently and with varying levels of trepidation.
Paying what will likely be his final official visits to Saudi Arabia, the United Kingdom and Germany, Obama hopes to extract far greater commitments in the terror fight. But it is unclear whether the climate in each location will allow for major breakthroughs in a war against ISIS that he's vowed to intensify during his final months in office.
"The only way to truly deal with global challenges is if everybody does their part. The nature of the threat from ISIL is not restricted to the targeting of one nation," said Ben Rhodes, Obama's deputy national security adviser, using the administration's term for ISIS. "We see ISIL posing a threat to the entire world, certainly posing a threat to both the (Gulf Cooperation Council) countries and to our European allies who we'll be meeting with on this trip."
'Complicated' ties with Saudi Arabia
To those ends, Obama arrives in the Saudi capital of Riyadh Wednesday looking for regional backing to bring stability to Syria and take out the ISIS terrorists that have found a sanctuary there.
His visit comes during a tenuous moment between Washington and the kingdom. A homegrown energy boom in the United States reduced American dependence on Saudi oil, leading to renewed questions about the value or rationale for traditionally close ties between the nations.
Saudi Arabia's strict form of Sunni Islam, known as Wahhabism, has come under new scrutiny. And the nuclear deal with Iran has led some in the kingdom to question their own place in the United States' foreign policy.
A new push to release documents that could explain Saudi Arabia's hand in the 9/11 attacks 15 years ago has the potential to degrade the relationship further.
The so-called "28 pages" were classified in an era when the U.S. relied far more on the kingdom's resources; as fears of upsetting the Saudi's has waned, a push to release the pages has gained steam.
Rhodes, who helped write the report of the 9/11 commission, described in broad terms the Saudi involvement this week in a podcast conversation with CNN commentator David Axelrod.
"Was the government actively trying to prevent (funding of al Qaeda) from happening? I think the answer is no," Rhodes said. "Not because they necessarily supported them, just because there was a bit of unregulated space, and rich people (there) can make different contributions."
Before any decision on declassification, pending legislation allowing victims of 9/11 to sue the Saudi government has prompted the Saudis to threaten selling off hundreds of millions of dollars in American investments. Obama's administration has lobbied hard against that law. But elsewhere, the President has shown a willingness to loosen the traditionally tight ties between Washington and Riyadh.
A March article in The Atlantic magazine reported Obama's deep frustrations with the kingdom, which author Jeffrey Goldberg reported Obama calling "complicated" in conversations with other foreign leaders. A quote from Obama insisting the country "share the neighborhood and institute some sort of cold peace" with Iran spurred outrage in Saudi Arabia.
That dynamic makes Obama's request for greater efforts against ISIS somewhat awkward, though U.S. officials insist the two countries are aligned in attempting to stabilize the region. During his stop, Obama is expected to announce new assistance to the region for ballistic missile defense and other security funding.
King Salman, the 80-year-old monarch in place for a little over a year, has shown new willingness to go after ISIS, but regional distractions, including a civil war in Yemen that saw heavy Saudi intervention, have forestalled a major contribution.
In a face-to-face with Salman on Wednesday, and group meetings with other Gulf leaders Thursday, Obama hopes to use a fragile ceasefire in Yemen to prod further action.
"The countries that have been involved in that fight, as they reach a political solution, will be able to focus more of their activities against ISIL and against al Qaeda. That's what we're discussing with them," said Rob Malley, Obama's coordinator for Middle East and Africa policy.
Europe on edge
Obama departs Riyadh Thursday for friendlier London, where after lunching with Queen Elizabeth II he'll turn his attention to his self-styled "bro," Prime Minister David Cameron.
Obama has been blunt in the past that Britain, along with other countries in Europe, must ramp up their counter-terror efforts if they hope to stave off the type of ISIS-linked attacks that have rocked Paris and Brussels within the past year.
In talks with Cameron on Friday and with German Chancellor Angela Merkel on Sunday, Obama hopes to find ways to better share intelligence that might help root out nascent terror cells in the West.
Both leaders, though, find themselves in moments of political upheaval. Merkel has faced a backlash for her generous policy welcoming migrants fleeing ISIS, a stance the Obama administration welcomed and intends to laud this week.
Cameron, meanwhile, is desperately working to repair his reputation after a tranche of documents related to offshore banking revealed details about his family finances. For Obama the timing is inconvenient: Cameron is also spearheading the campaign to keep his country as a member of the E.U. ahead of a referendum vote in June.
It's a position Obama shares and is expected to advocate for during his relatively lengthy stay in the British capital. That approach carries risks, however, including giving the appearance of meddling in Britain's affairs, a charge Obama typically goes to lengths to avoid.
London Mayor Boris Johnson had already accused Obama of being "nakedly hypocritical" ahead of the visit.
"We have no closer friend in the world, and if we are asked our view as a friend, we will offer it," said Rhodes.
"That's the approach he'll take," he continued, "one of being very mindful and deferential to the fact that this is a decision for the British people, but also being very straightforward and candid as a friend as to why the United States believes that it is good for the United Kingdom to remain in the European Union."
Unknowns back home
U.S. officials noted that Obama is expecting questions from leaders -- and ordinary citizens -- about the race to replace him in America. The President has already warned that divisive rhetoric from GOP candidates has harmed America abroad.
"I am getting questions constantly from foreign leaders about some of the wackier suggestions that are being made," he said earlier this month.
Obama is also confronting world leaders already looking to next year as they consider their U.S. ties.
"You have an American president going out to these countries, and everyone looking at the political debate going on in the U.S. has to realize this is not the voice of the future," said Anthony H. Cordesman, the Arleigh A. Burke Chair in Strategy at the Center for Strategic and International Studies.
Republican front-runner Donald Trump has widely mocked U.S. alliances in the Middle East and Europe, claiming Saudi Arabia wouldn't survive without "the cloak of American protection" and deeming NATO "obsolete."
His main rival, Texas Sen. Ted Cruz, has issued sharp warnings to Saudi Arabia for their still-unclear role in funding terrorism. Sen. Bernie Sanders, running for the Democratic nomination, said he supports the legislation allowing 9/11 victims' families to sue Saudi Arabia, as well as other foreign governments, but is otherwise unknown to most of the players abroad.
Former Secretary of State Hillary Clinton remains the most familiar candidate among allies abroad.
"If it's Hillary Clinton, then it's business as usual," said Faisal al Yafai, chief columnist at The National newspaper in the United Arab Emirates. "If it's the others, and particularly the Republicans, that I think inspires some element of concern."