When G7 leaders meet in Hiroshima this week, they won't be alone: eight non-members including major developing economies have been invited in a bid to sway opinion on Russia and China.
Regional powerhouses India and Brazil will attend along with ASEAN host Indonesia, Pacific Island Forum chair the Cook Islands, African Union chair Comoros, Vietnam, South Korea and Australia.
They will take part in a dedicated outreach session as well as bilateral meetings intended to bring some reluctant leaders into the fold in opposition to Russia's war in Ukraine and Beijing's growing military assertiveness.
"It's increasingly the case that the guest lists of these things are quite large," but "not just anybody is invited," said Tristen Naylor, an assistant professor at the University of Cambridge and an expert on summits and diplomacy.
The G7 wants to be seen as a "club dedicated to the protection of democracy" and wants broader backing for its support of Ukraine and efforts to counter China, he told AFP.
India is a long-time military ally of Moscow and its "ambivalent position" on the war in Ukraine is out of step with most other leading democracies, Naylor said.
"So this is very much a chance for the G7 to at least try to bring India on side," he said, warning it would be a difficult task.
While Ukrainian President Volodymyr Zelensky is expected to address the summit remotely, a Russian delegation will be in Delhi this November for the G20 summit, and few expect Prime Minister Narendra Modi to make any sudden policy shifts.
- 'Pushing back on Chinese influence' -
Another "principal aim" of the summit will be to offer an alternative to China's huge infrastructure investments around the world, Naylor said.
Brazilian President Luiz Inacio Lula da Silva was in Beijing last month, where his country's top trading partner pledged to pursue "high-quality development" that would "unlock opportunities for Brazil".
Lula, who took aim at the US dollar on the trip, is far from the only leader being courted by China, and G7 allies are keen to show they can offer an alternative.
"This concept of pushing back on Chinese influence, sustaining the rules-based order in the Global South" will be a big part of the summit, said Chris Johnstone, Japan chair at the Center of Strategic and International Studies.
Japan has already been doing legwork on that front, with Prime Minister Fumio Kishida and foreign minister Yoshimasa Hayashi making a flurry of trips this year to countries in Africa, Southeast Asia, Latin America and Pacific Island nations.
In Delhi in March, Kishida pledged public and private capital worth $75 billion towards infrastructure in the Asia-Pacific region by 2030.
- 'Movement to divide' -
He has also hammered home the message that Russia's invasion of Ukraine is the "chief cause" of the soaring food and energy prices that have hit developing countries hardest.
"But there's a movement to divide the world by giving the wrong impression that the G7's sanctions against Russia" are to blame, Kishida told reporters in Mozambique.
Tokyo and Seoul are in the process of patching up long-frayed ties, and Kishida is expected to hold trilateral talks with his Korean and US counterparts on the sidelines of the summit.
Talks could also be held in Hiroshima between the "Quad" grouping of Japan, Australia, the United States and India.
But not all invitees are likely to be in such a conciliatory mood, according to Yuichi Hosoya, professor of international politics at Keio University.
"It should not be taken for granted that they will offer broad and strong support" on Ukraine and other G7 initiatives, he wrote in an article last month.
"Japan should make efforts to understand precisely what each of the countries are looking for, recognise the diversity of the international community, and make specific contributions."