So the first half of 2012 has passed. Which brings us closer to the end of the world - if the Mayan calendar is to be believed. We have another six months to find out if those predictions are correct. Meanwhile, life goes on with its cycle of news, good and bad. Fighting continues in Syria and Afghanistan. So do global economic woes, particularly in Europe. This just shows that this year is set to be no less chaotic than many others in the past. Amid so much upheaval and uncertainty, we are also seeing frequent leadership changes. As a global citizen and Young Post reader, you need to be aware of what's happening around you. So let's take a look at who will be in charge - if we successfully make it to the end of 2012, and beyond. C.Y. Leung - Hong Kong Hong Kong's political landscape has just turned a new page. Former surveyor Leung Chun-ying beat his two rivals - Henry Tang Ying-yen and Albert Ho Chun-yan - in April's election and has just officially become chief executive. At the time of his victory Leung was seen as the most articulate and practical of the three candidates. Two of his election promises were to fix the rich-poor gap, and high property prices. But pan-democrats worry Leung is aligning himself too closely with Beijing. Just before his inauguration, his image took another hit after six illegal structures were discovered at his luxury home on The Peak. Xi Jinping - China The mainland will see a big leadership change this year. Xi Jinping , the current Vice-President, is tipped to succeed Hu Jintao as president. A sign of his growing status was evident when he visited the United States in February. Xi is regarded as an open-minded leader. He has so far received a warm welcome from the West. Early in his career, in 1985, Xi visited Iowa, in the US, as head of an animal feed delegation. Yet few people - apart from some high-ranking party officials - really know who will prevail and take the top position until it is announced. Obama vs Romney - United States America's presidential election will be held on November 6. Barack Obama, who is a Democrat, became the 44th president of the United States following his election victory in 2008. He is the first African-American to be president and will be hoping to secure a second and final term. Obama is seen as liberal-minded and will be facing off against Republican Mitt Romney. Obama has shown he is good at playing basketball. Romney has shown he is good at ... saying no - both to America's universal healthcare bill and same-sex marriage. This year's presidential election is important because the US has a huge influence on the world, including China. The two rivals have very different views about how the US should handle Beijing's rising global influence. Francois Hollande - France Francois Hollande defeated incumbent president Nicholas Sarkozy to claim France's top job on May 6. Hollande, a socialist, has been depicted as a modest man compared to the more flamboyant Sarkozy. He took charge on May 15. He will play a key role in trying to solve the ongoing euro crisis. Many European nations share a common currency, the euro. But several nations - including Spain, Italy and Greece - are heavily in debt. The richer nations, particularly Germany, are unhappy about having to bail out these weaker nations. At his first European Union summit, Hollande proposed strong measures, which have strained diplomatic relations with other euro nations. He believes in radical growth plans for Greece, for example, instead of endless austerity measures. Antonis Samaras - Greece Greece has been in a state of chaos for months. Plagued by the euro crisis, the country also failed to reach a consensus to select its own leader before Antonis Samaras. The biggest bone of contention is the government's austerity measures. Most citizens dislike austerity, and many of them voted for Syriza, an opposition party that came second in the election thanks to its stance against austerity. A protest vote punished other parties that support the policy. Samaras' party, New Democracy, came first, but has failed to gain a majority it would need to rule. ND will align with Pasok, a pro-austerity party, to form a government, which plans to keep Greece in the eurozone. It also wants to receive further EU bailouts.Vladimir Putin - Russia Vladimir Putin was president of Russia before. He served two four-year terms from 2000 to 2008. A legal limit on holding the job for no more than two terms forced him to step down and become prime minister. In March, he was re-elected as president - this time for a new extended term of six years. His opponents accused him of vote rigging. There were protests both before and after his re-election.