World leaders are finalizing preparations for this month’s G20 summit in Osaka, Japan, potentially the most important since the 2009 meeting in London during the storm of the international financial crisis. Presidents and prime ministers will be in attendance from the US, China, Germany, India, Japan, Indonesia, Australia, Russia, Brazil, United Kingdom, Saudi Arabia, South Africa, Turkey, France, Italy, Germany, Canada, South Korea, Argentina, Mexico, and the EU. These countries account for about 90 percent of global gross domestic product, 80 percent of world trade and about 66 percent of the world’s population. Recent summits, especially the one in Hamburg in 2017, have been perhaps most memorable for the divisions within the G20 powers, especially with regard to the US and key EU countries, over issues such as international trade, migration and climate change. One flashpoint has been the at times strong disagreement over global trade. In Hamburg, for instance, German Chancellor Angela Merkel pushed for a strong G20 re-affirmation of international trade, while US President Donald Trump secured language in the end-of-summit communique that ensures countries can protect their markets with “legitimate trade-defense instruments.” This same topic is likely to be central to the narrative of this year’s meeting, with Beijing and Washington having been embroiled for well over a year in what could yet descend into a trade war, with both sides having already imposed hundreds of billions of dollars of tariffs. While a deal appeared imminent in March there has since been a frosty air, with Trump accusing Beijing of “breaking the deal” by backtracking on key issues, including Chinese state subsidies. Trump has repeatedly expressed optimism that a breakthrough might yet be reached, and the G20 forum could be important to this in at least two respects. First, the two sides brokered a truce at last year’s event in Argentina, agreeing to delay the imposition of further tariffs in a move that kickstarted the flurry of negotiations this year that gave rise to the hopes of an agreement. A second reason the G20 could be important is that it offers a relatively rare forum for Xi Jinping and Trump to meet face to face. Given the importance the US president places on such personal interaction and summitry, it remains possible that the mood music in Japan could yet be more positive than many expect, with the outside chance of a breakthrough with Xi. The significant amount of attention on this year’s G20 highlights, yet again, that since the 2008-09 financial crisis the body is widely perceived to have seized the mantle from the G7 as the premier forum for international economic cooperation and global economic governance. Andrew Hammond In this tricky, uncertain context one indicator of the summit’s success would be the ability to break through the disagreements that do arise among the leaders and agree a powerful end-of-summit communique. All previous G20 sessions have done so, but recent global summitry — including last year’s G7 in Canada and the Asia-Pacific Economic Cooperation meeting in Papua New Guinea last November — both ended with unprecedented failures to agree communiques. Another reason this summit will be noteworthy is that it will be the final G20 for several world leaders, including British Prime Minister Theresa May, who will leave office soon. Other leaders who may lose power in the next year are Canadian Prime Minister Justin Trudeau and Merkel. The significant amount of attention on this year’s G20 highlights, yet again, that since the 2008-09 financial crisis the body is widely perceived to have seized the mantle from the G7 as the premier forum for international economic cooperation and global economic governance. It is now more than a decade since the G20 was upgraded from a gathering of finance ministers to one at which heads of state meet too — a move that was greeted with considerable fanfare, such as from the French president Nicolas Sarkozy, who claimed that “the G20 foreshadows the planetary governance of the 21st century.” Yet the fact is that the forum has failed so far to realize the full scale of the ambition thrust upon it by some at the height of the international financial crisis. A key reason for this failure is that the G20 meetings have no formal mechanisms to ensure enforcement of agreements by world leaders. There also remain concerns among states outside the G20 about the club’s composition; the members were originally selected in the late 1990s by the US and its G7 colleagues. While they were nominally selected according to criteria such as population and GDP, the group has been criticized for omissions such as Nigeria, sometimes called the “giant of Africa,” which has three times the population of South Africa. Former Norwegian foreign minister Jonas Gahr Store has gone so far as to call the G20 “one of the greatest setbacks since the Second World War,” in that it undermines the UN’s universal sense of multilateralism. Reflecting this, the UN General Assembly convened a rival UN Conference on the Global Economic Crisis in 2009 to provide an alternative forum. Nevertheless, the G20 continues to be prized by its members, as the session in Japan will show. This year’s event could be especially memorable given the possibility of tensions easing or escalating significantly between Trump and Xi in the context of the long-running US-China trade tantrum.