World leaders to watch: twelve world leaders who are sure to make headlines in the year ahead.

• Author: Smith, Patricia
• Position: INTERNATIONAL

Xi Jinping Since: 2013

China's vice president since 2008, Xi Jinping (shee jinping), will become president after Hu Jintao steps down in early 2013. China has the world's largest population, with 796 million workers fueling its booming economy. In 2010, China passed Japan to become the world's second-largest economy, after the U.S. But China remains a one-party authoritarian state. Political dissidents are routinely jailed, and the Communist leadership censors the Internet, blocking thousands of websites, including Facebook. Xi, 59, is thought unlikely to make radical changes.

AFGHANISTAN

Hamid Karzai Since: 2001

Karzai has been in power since the U.S. and its allies invaded Afghanistan to overthrow the Taliban (a radical Muslim group that harbored AI Qaeda) following the 9/11 terrorist attacks. There are currently 68,000 U.S. troops in Afghanistan trying to stabilize the country; more than 2,000 have been killed. Karzai, 54, and American officials want to prevent Afghanistan from descending into chaos after the scheduled departure of U.S. forces by the end of 2014. Karzars term also ends in 2014.

RUSSIA

Vladimir Putin Since: 2000

By playing loose with the rules, Putin has run the show in Russia for 12 years, as either president or prime minister; his current term lasts until 2018. As Russia's leader, the 60-year-old Putin has become increasingly authoritarian, consolidating control and cracking down on dissent. Protesters have staged several anti-Putin rallies since his re-election. Despite increasingly tense relations, the U.S. needs Russia's cooperation on issues such as containing nuclear threats from Iran and North Korea.

EGYPT

Mohamed Morsi Since: 2012

A Year and a half after Egyptians ousted longtime authoritarian President Hosni Mubarak, Morsi became the country's first democratically elected president. Morsi, 61, is a member of Egypt's formerly outlawed Muslim Brotherhood. He has vowed to respect Egypt's Christian minority and maintain its peace treaty with Israel. But concerns remain about whether Morsrs government will adopt a more conservative brand of Islam. Meanwhile, Egypt's economy, which depends on tourism, has been struggling since the revolution.

MEXICO

Enrique Pena Nieto Since: 2012

Pena Nieto, 46, was elected president in July. His biggest challenge is the ongoing war against powerful drug cartels that has killed more than 47,000 people since 2006. While many Mexicans remain poor, Mexico's middle class has grown...