The international pecking order is usually defined by economic and military might. That puts the US at the top of the pile, with China gaining fast in second place.But when it comes to tackling long-term global challenges such as climate change, poverty or peacemaking, it’s also vital to identify which leaders are likely to stick around.Whether democrats, dictators or somewhere in between, they’re all balanced atop a shifting ziggurat of potential rivals. And only those with the home front under control are in a position to make meaningful promises for the 2020s or beyond. That’s why France’s Emmanuel Macron can map out a seven-year program for reforming the European Union while Theresa May can’t look beyond the date of Britain’s exit from the bloc next year.So for an alternative take on who really matters in global affairs, we picked 16 countries and analyzed how long their leaders might hold off the palace coups, election defeats or waning powers that end political careers.Prime Minister Narendra Modi dominates India’s political landscape and is widely predicted to win the next national election in 2019. With five-year terms, that means he could rule over his country’s 1.3 billion people until at least 2024—possibly longer.Although he lacks the upper-house majority necessary for big structural reforms, Modi’s Hindu nationalist Bharatiya Janata Party has proven its popularity, winning numerous state-level elections since he came to power in 2014.Modi, 67, is by far the most popular Indian politician. The opposition Congress Party is weak and lacks a charismatic leader, while regional rivals are vulnerable to the BJP’s formidable election machine. His party’s policies, even when economically disruptive, are still popular with the masses.“Certainly, it seems like they will come back into power in 2019 given their success in state elections and massive popularity—and in 2024, that’s also on the agenda,” said Reshmi Khurana, a Singapore-base managing director at the consultancy Kroll. “The absence of a strong opposition makes that highly possible.”After the Chinese Communist Party’s move to repeal presidential term limits in February, the main question is how long will President Xi Jinping stay.The constitutional provision barring heads of state from more than two consecutive terms was the only formal barrier keeping Xi, 64, from staying on past 2023. After being elevated to the same status as Mao Zedong in October, when his name was written into the Communist Party charter, he’s positioned to influence China for decades to come.“Xi has set out his ambition to lead China for the long-term, at least through the 2020s, I think we can assume, if he remains healthy,” said Tom Rafferty, the Economist Intelligence Unit’s regional manager for China. “Event risk still pertains, however. A bout of economic instability or a mishandled international confrontation—neither of which can be discounted—would weaken his position internally and give an opportunity to others.”Over his 18-year rule, President Vladimir Putin has methodically neutralized any threat to his power, from ambitious oligarchs to Chechen separatists to Western sanctions.With an approval rating over 80 percent and total control over the political arena and national media, 65-year-old Putin is sure to win another six-year term on Sunday. But in 2024 a constitutional limit should force him to give up the presidency. He’s already sidestepped those rules once, and he’s suggested that’s not something he’d do again. The challenge is to ensure his system and his inner circle are safe after he goes.“Putin wants to keep the levers of influence to give him a veto over his successor’s decisions,” said Tatiana Stanovaya, a political analyst at the R.Politik think tank. “He has to build a system that will maintain the status quo even when he isn’t president—the Putin regime must remain even without Putin.”Crown Prince Mohammed bin Salman isn’t king yet but he’s already effectively running Saudi Arabia at the age of 32 and he could conceivably govern for another half century—his father, King Salman, is 82, and former King Abdullah died at 90.Even skeptics say that the prince has cleverly outmaneuvered competitors, positioning himself to rule the absolute monarchy for decades by pushing aside other royals, though he has made enemies along the way.“If he remains healthy and the politics, culture, society and economics of the country and the region go in a way that would support a long-term ruler, he could be in leadership for 50-plus years,” said Paul Sullivan, a Middle East specialist at Georgetown University in Washington. “This is very rare.”A coup, assassination or war with the U.S. appear to be the main risks to Kim Jong Un . But if none of them topple him, he will probably maintain his iron grip on North Korea for decades, just as his father and grandfather did.Kim is believed to be in his thirties, so his natural lifespan could easily stretch for another forty or fifty years. Though his weight issues add an element of risk, his father, Kim Jong Il, died at 70, while his grandfather, Kim Il Sung, lived to be 82.“I do not see any likely scenario in the near future that would undermine Kim Jong Un’s power,” said Sebastian Maslow, an assistant professor at Kobe University. “Unless we witness action by U.S. or South Korean special military units to remove him by force, we will have to deal with Kim Jong Un as North Korean leader for some time to come.”Recep Tayyip Erdogan could become even more influential if he’s reelected in November 2019, when more power will be concentrated in the Turkish presidency.Prime minister from 2003 to 2014 before becoming the country’s first directly elected president, the 64-year-old Erdogan survived a coup attempt in 2016 and enjoys strong support from voters as well as the backing of a nationalist opposition party. Although Erdogan is theoretically limited to two five-year terms, he can stretch that if a snap election is called during his second term.A New York trial last year over the role of some Turkish nationals in an alleged multi-billion dollar conspiracy to undermine U.S. sanctions on Iran has fed the narrative of western conspiracy against Turkey and allowed Erdogan to tighten his grip on power.“Erdogan is forming political alliances and overhauling laws to get elected as the first executive president,” Nihat Ali Ozcan, an analyst at the Ankara-based Economic Policy Research Foundation of Turkey, said. “If he wins, Erdogan could possibly stay in power at least another decade.”