Title: Israeli prime minister Country: Israel Age: 66 Reelected this year as the prime minister of Israel, Benjamin Netanyahu recently compared the Middle East to Game of Thrones. It isn't a game he's always played well — disputes over the Iran deal and the Israeli-Palestinian conflict have left US-Israeli relations at a crisis point. But Israel has remained relatively stable during a time of turmoil throughout the Middle East, and Netanyahu has dominated his country's politics like few Israeli leaders. Overall, many say that Netanyahu has done a good job of boosting Israel's economy and putting the country at the forefront of technological and medical advances. Even so, the fallout over the Iran nuclear deal, and his strained relations with Washington, don't fare well for his legacy.Title: President of South Korea Country: South Korea Age: 63 South Korean President Park Geun-hye is the first female leader of her country — an especially impressive accomplishment considering South Korea has the highest level of gender inequality in the developed world. Her election generated the nation’s highest turnout rate in 15 years. Park has the difficult but critical responsibility of diffusing threats from the ever-combative North Korea. Last year, she tried to get her mercurial neighbors to the north to abandon their nuclear-weapons program by promising humanitarian aid and an investment in its weak industries, but to no avail. Park has flexed her muscles by testing missiles that can reach all of North Korea, but Kim Jong-un hasn't blinked, and hasn't quashed any nuclear ambitions.Title: Supreme Leader of Iran Country: Iran Age: 76 Ayatollah Ali Khamenei, who has been the ultimate authority in Iran since 1989, is openly opposed to Western influence in both his country and the broader Middle East. A hardliner even within Iran's clerical regime, Khamenei has long championed the slogan Death to America, and he has sought to position Tehran as both a geopolitical and ideological enemy of the US and Israel. After over 18 months of negotiations, Khamenei conditionally agreed to a landmark nuclear deal reached with six world powers this past July. The deal outlines Iran's promise to curb its nuclear program in exchange for the US and its partners lifting economic sanctions. The agreement is set to open Iran's economy to outside investment and has generally raised the prestige of Khamenei's government, which is quickly shaking its status as one of the world's pariah states.Title: King of Saudi Arabia Country: Saudi Arabia Age: 79 Salman bin Abdulaziz al Saud took the throne as king of Saudi Arabia in January after the death of his half-brother. His short tenure hasn't been without controversy: Eight of the 12 surviving sons of the country's founding monarch reportedly support a coup to oust King Salman and replace him with his younger brother, Prince Ahmed bin Abdulaziz, a sign tensions are at a high within the royal family. But as the leader of Saudi Arabia, King Salman wields incredible influence over the Middle East and his country's massive oil reserves. Even with oil at historically low prices, Saudi Arabia — the world's largest oil exporter — continues to ramp up production to depress prices and protect its global market share, despite the negative effect it has on the global oil economy.Title: President of Brazil Country: Brazil Age: 67 Dilma Rousseff, Brazil's first female president, leads the largest country in Latin America and the seventh-largest economy in the world. Rousseff is credited with nearly eradicating extreme poverty in Brazil during her first term by raising the monthly stipend for struggling families. But Rousseff has hit a rough patch lately, and it appears to be getting worse. Protests broke out and gained traction in March in part because of Brazil's crumbling economy. The country's growth has plummeted — low commodity prices, high interest rates, and austerity measures are partly to blame — and it officially entered a recession in 2015. The value of its currency devalued by 45% this year through mid-November. Also contributing to her near record-low approval rating: A group of high-profile lawyers filed for the impeachment of Rousseff in October in connection to the corruption scandal involving the state-run oil company Petrobras (Rousseff has maintained her innocence).Title: Prime minister of Japan Country: Japan Age: 61 Three years into his second term as prime minister of Japan, Shinzo Abe continues to craft bold plans for his country's future. At the forefront is a desire to bring the excitement and innovation of Silicon Valley to Japan to jump start the country's fading tech sector. In a recent visit to the US, Abe met with tech titans like Facebook CEO Mark Zuckerberg to learn how we can take Silicon Valley's ways and make them work in Japan. This plan comes on top of Abenomics, the three-pronged approach the prime minister implemented to boost Japan's economy upon starting his second term in 2012. On the same visit to the US in April, Abe also became the first Japanese prime minister to address a joint session of US Congress, which he used to push forward talks on the Trans-Pacific Partnership, a trade deal that would bring together nations including Australia, the US, Japan, Mexico, and Vietnam.Title: President of France Country: France Age: 61 It hasn’t been an easy 12 months for French President Francois Hollande. He's dealt with multiple terrorist attacks in Paris, stepped up France’s role in the fight against ISIS, and instituted reforms to the country’s social policy, like extending the retirement age for private-sector workers. Hollande also saw his approval ratings continue to dip down to 20% as the year wore on. Though he’s slowly making progress in his attempts to lift both French morale and favor among his constituents, Hollande has a long way to go. But he still commands the fifth-richest nation on the continent and one of the most influential members of the EU, giving him immense power regardless of approval ratings.Title: UK prime minister Country: UK Age: 49 Reelected for a second term in May with a majority, British Prime Minister David Cameron has strengthened his negotiating position with the EU. Cameron is committed to gaining concessions from the 28-nation bloc, including looser rules on welfare for immigrants an regulation of businesses, but many Britons are skeptical that the prime minister can secure a better deal. He's promised an in or out referendum for the country, but Cameron believes remaining in the EU is in his country's best interest and has been visiting EU leaders to sell them on his proposal. Cameron met with Queen Elizabeth after the election to talk about his plan for the next five years, which, in addition to renegotiating his country's terms with the EU, includes a controversial plan to crack down on immigration.Title: Pope Country: Vatican City Age: 78 The leader of the Catholic faith, which has more than 1 billion followers worldwide, has staked more outspoken, progressive views on public issues than popes before him. At an address to the US Congress in September, Pope Francis called on lawmakers to empathize with immigrants and refugees and to welcome them into their country. To the delight of liberal Catholics, he urged more action to stop the effects of climate change and endorsed a more forgiving stance on divorce and homosexuality. Many American Catholics predict that within the next 35 years the church will approve of contraception, married priests, and recognition of same-sex marriages, according to a recent Pew survey. Title: Indian prime minister Country: India Age: 65 Now in his second year as prime minister of India, Narendra Modi is introducing initiatives to improve the lives of the 1.2 billion people who make up the world’s largest democracy. In May, he announced plans to reform and modernize the government and business sectors by implementing a uniform sales tax and boosting foreign direct investment to India. Modi, the second-most followed political leader on Twitter behind Barack Obama, is also pushing India to integrate with the digital world. He believes tech innovation holds the key to lifting India out of poverty, and he traveled to Silicon Valley in September seeking advice and help from tech executives at companies like Google and Facebook.Title: Chancellor of Germany Country: Germany Age: 61 With 10 years and three terms in office under her belt, German Chancellor Angela Merkel is a strong and indispensable leader in Europe. She has faced a host of challenges throughout her tenure and come out on top: She helped hold the eurozone together during the financial collapse and global recession, she has stood up to Russian President Vladimir Putin in his aggression toward Ukraine, and, currently, she's managing Europe's refugee crisis. At her hand, Germany stands above the rest of Europe with a strong economy and low unemployment rate. Though she's not universally liked, Merkel has proved a stabilizing force amid turmoil.Title: Russian president Country: Russia Age: 62 Approval ratings for Vladimir Putin, Russia's president and former prime minister, reached an all-time high in October: 89.9%. After seizing Crimea last year in the wake of the Ukrainian Revolution, Putin is determined to resurrect Russia as a superpower.In the past year, he's supported a pro-Russian insurgency in eastern Ukraine, and launched a military operation in support of Syria's Bashar al-Assad. Unlike with most Western heads of state, Putin's control over Russia is subject to few constitutional checks and balances. At the annual UN meeting in late September, Putin criticized Obama, asserting that US interventions have backfired in the Middle East, creating a haven for extremists and terrorists. Shortly after, Putin launched the Russian air campaign to target Islamic forces in Syria and weaken rebellion against the country’s president. The airstrikes are costing Russia an estimated $2.5 million a day, and are quickly escalating tensions with Western powers.Title: President of the People's Republic of China Country: China Age: 62 Xi Jinping, the general secretary of China’s Communist Party, has been labeled by many the most powerful Chinese leader since Mao Zedong. Considering the domestic grip he’s secured in just three years since becoming president of the world’s largest country — nearly 1.4 billion people — it’s hard to argue. Xi holds at least 10 titles governing the world superpower (some of which he created), overseeing everything from the military and the internet to the economy. That economy has stalled, and the nation’s stock market endured a tumultuous summer requiring a bailout that may have topped $200 billion. Still, China’s growth in recent years puts it in elite company, and by one measure its economy even eclipses that of the US, according to the IMF. Xi has fulfilled a vow to wage an extensive and controversial anticorruption campaign within the country. He has investigated hundreds of thousands of people and locked away some high-ranking party officials for life — his former political enemies among them.Title: US president Country: US Age: 54 President Barack Obama presides over the world's most influential country, giving him unparalleled responsibility and power. He's caretaker of the largest economy, and he's helped nurse it back to health since the financial crisis. Since taking office in early 2009 — amid a full-blown recession — the US has grown its GDP by $3 trillion, to $17.4 trillion, and in October unemployment hit 5%, the lowest mark since 2008. His legacy-making overhaul of the health-care system has helped trim the uninsured rate by a third, and it has now survived multiple Supreme Court challenges. Obama's international track record is mixed. As commander-in-chief of the world's largest military — more than 2 million active and reserve forces and a defense budget of $560 billion — he's taken heat for failing to deal adequately with the growing turbulence in the Middle East, highlighted by the bloody Syrian civil war, the rise of ISIS, and the Taliban's growing strength in Afghanistan. Relations with longtime ally Israel have grown icy. Yet his sway in foreign affairs is still strong, as evidenced by his historic move to warm ties with Cuba and the momentous nuclear deal he brokered with Iran. He may have just a year left in office, but Obama isn't sitting idle: In November he flexed his power again, killing off the controversial Keystone XL pipeline proposal once and for all, arguing it would have harmed the environment without improving US energy security.