G7 leaders meeting in Japan this week are expected to grapple with issues ranging from migration and the Syrian conflict to the economic slowdown, but their talks will likely be overshadowed by US President Barack Obama's visit to Hiroshima.
The G7 summits - bringing together the leaders of Britain, Canada, France, Germany, Italy, Japan, the United States and the European Union - are seen as a chance to set global priorities and seek a common approach on key challenges.
During a recent visit to Brussels, Japanese Prime Minister Shinzo Abe said the G7 should "act in unison" to defend their common values.
But each leader will be coming to the Japanese province of Ise-Shima with different baggage, as rare instability looms over the club's most solid members.
For Obama, it will be his last G7 summit, ahead of elections in November that many fear could bring a new isolationist president to the White House in the form of Republican frontrunner Donald Trump.
British Prime Minister David Cameron is weeks away from a referendum on his country's future in the EU that is being nervously watched from Brussels and beyond, while his European partners are grappling with the challenges of migration and terrorism.
German Chancellor Angela Merkel is counting on the G7 to show solidarity on both issues, according to government sources in Berlin.
Migration is "one of the defining global challenges of our century," European Commission President Jean-Claude Juncker said during Abe's visit. "The international community must do its fair share," he added.
However, the issue is seen as a low priority for the host Japan, which took in just 27 refugees out of 7,500 applicants last year.
Nonetheless, analysts see the summit as a chance for Abe to boost his country's role internationally and infuse the G7 format with new energy.
Earlier this month, he toured Europe laying out his priorities, even stopping off to visit Russian President Vladimir Putin, whose country was expelled from the club of leading nations in 2014 over Moscow's annexation of Ukraine's Crimean peninsula.
The G7 leaders are expected to stand firm in their response to Russia, which is believed to be supporting separatists in eastern Ukraine. EU officials expect the summit outcome to shape an upcoming debate in Europe on the extension of sanctions against Moscow.
Abe's main rallying cry has focused on the economy, advocating a boost in public spending to tackle the global slowdown. But Merkel rejected the idea at recent talks in Berlin, calling instead for a policy mix involving structural reforms.
Abe is under pressure domestically, as his "Abenomics" policies have failed to revitalize long-term growth. Japan is beset by deflation, while stock prices have fallen amid concerns that a rise in the yen is hurting exports.
The issue is also a bone of contention internationally, with Washington wary of moves by Tokyo - and Beijing - aimed at keeping their currencies artificially low.
Meanwhile, the EU hopes the summit will give new impetus to free trade talks.
The bloc is stuck in tough negotiations with the US and Japan, while public opinion is swinging against the deals, amid fears that trade liberalization exposes domestic industry to cheap competition from abroad.
The issue has been underscored by an international spat with China over its steel exports, with a global oversupply in steel driving down prices and leading to job cuts.
The issue is expected to make it onto the G7 agenda, with China - which is not at the table - accused of exacerbating the problem with unfairly cheap exports and steel sector subsidies.
Beijing also stands at the centre of a regional dispute over the South China Sea, a key shipping lane believed to be rich in marine resources that is claimed in various parts by five neighbouring countries.
Last month, G7 foreign ministers provoked a strong reaction from China when they opposed any "intimidating, coercive or provocative unilateral actions." The summit will likely reconfirm that message, according to a senior EU official.
But many will focus on events after the two-day summit ends on Friday, when Obama will become the first sitting US president to visit Hiroshima, one of two Japanese cities that Washington dropped atomic bombs on during World War II.
Those expecting an apology will be disappointed, however, with Obama walking a tightrope between respect for the victims and sensitivities back home, where the bomb is seen as having been a necessary step to end the war.
"The purpose of the visit is not to re-litigate issues of the past; it's to build a better future," noted Daniel Russel, US assistant secretary of state for East Asian and Pacific affairs.