South Sudan Crisis Explained (Like You're an Idiot) About 1,000 people are dead in an increasingly bloody conflict in South Sudan.

Dec. 23, 2013  -- Helicopters evacuated more than a dozen U.S. citizens from South Sudan Sunday, but thousands of other foreigners will likely spend Christmas in the world's youngest country as an ethnic conflict there spirals toward civil war.

The United Nations estimates that nearly 1,000 people have been killed, and 45,000 displaced, in clashes between the Dinka and Nuer tribes since violence began Dec. 15 amid rumors of a power grab and a failed coup attempt.

READ: Trapped U.S. Relief Workers Flown Out of Violence-Torn South Sudan

In a deeply impoverished nation that sits on millions of barrels of untapped oil, the conflict is years in the making. It's complicated, but we promise to talk really, really slowly.

South Sudan? Never heard of it. The only Sudan I care about is the one with George Clooney in it.

South Sudan is the world's newest country. After a referendum in 2011, 98 percent of the East African country's population voted to declare independence from Sudan. The people of South Sudan are largely black and Christian. For years, they fought a bloody war for independence from Sudan, a nation ruled by Arab Muslims.

(The Sudanese government in Karthoum had cracked down on non-Muslim populations for years, including a bloody conflict in the western region of Darfur. That's where George Clooney focused attention in the early 2000s.)

South Sudan is rich in oil reserves. "Since independence, South Sudan has struggled with good governance and nation building and has attempted to control rebel militia groups operating in its territory. Economic conditions have deteriorated since January 2012 when the government decided to shut down oil production following bilateral disagreements with Sudan," according to the CIA.

Who is in charge over there? It sounds like the Wild West.

Funny you should mention the Wild West. South Sudan's president is Salva Kiir, an ethnic Dinka, who has worn the black cowboy hat given to him as a gift by President George W. Bush every day since receiving it in 2006.

Kiir blames the fighting, which began Dec. 15 and has resulted in the deaths of 1,000 people, on a failed coup by former Vice President Riek Machar, an ethnic Nuer. Other officials say the fighting began as a turf war between Dinka and Nuer members of the presidential guard, which spread throughout the country.

When members of a Nuer ethnic militia began fighting in Bor, a large city populated mainly by Dinkas, the death toll rapidly rose and foreign governments sought to airlift their citizens.

Good thing we're getting the Americans out of there. Seal Team Six, heck yeah!

The United States has evacuated slightly more than 300 known U.S. citizens from Bor in the past week. Civilian helicopters and those operated by the U.N. airlifted about 15 Americans Sunday, but the operation was far from flawless.

Three Navy-operated Osprey aircraft, the ones that fly like planes but land like helicopters, were shot at Saturday while landing in Bor to pick up U.S. citizens. They were special forces operators but not from Seal Team Six. Four service members were injured in the attack before the mission was called off.

Thousands of other foreigners, including Britons, Australians, Canadians and South Africans, are expected to remain in the country for at least several more days before their countries can evacuate them.

That doesn't sound like a happy Christmas.

U.S. Secretary of State John Kerry and Donald Booth, the U.S. envoy for South Sudan, have pressured President Kiir to call for a Christmas ceasefire. Most observers, however, believe that fighting will continue.

Thounsands of internally displaced people have sought protection at U.N .bases in Bor and the country's capital, Juba.

UN Secretary-General Ban Ki-moon has asked the Security Council to send additional troops, police and logistical assets to South Sudan and move U.N. peacekeepers from elsewhere in Africa.

"Those responsible at the senior level will be held personally accountable and face the consequences, even if they claim they had no knowledge of the attacks," Ban said in a statement.