8. Falklands
The Falklands Islands are part of another dispute between the UK and Argentina. The islands changed hands numerous times in the years prior to 1833 when the UK took over sovereignty and has maintained it ever since. The UK claim to the Falklands goes all the way back to 1690 but Argentina believes that they have a claim to the islands as well. Argentina did manage to take control of the Falklands for a brief period in 1833.
When British colonies began to get independence following World War II, Argentina raised the issue of sovereignty over the Falklands with the UN. The UN told the two countries to come up with an arrangement on their own. The two countries tried to come to an agreement and even worked together. Argentina would supply oil to the Falklands and the British built a runway for Argentinian airlines to use. But neither country would agree on sovereignty, largely because the people living in the Falklands wanted to remain under British rule.
In 1982, Argentina was suffering an economic crisis and decided it was time to take back the Falklands. They launched an amphibious attack on April 1st and took control of the islands. The international community condemned the action, to the point where several countries came to the aid of the British during the Falklands War. The war lasted a mere 10 weeks and ended with Argentinian surrender.
In 2009, the British government decided there would be no further talks about the future of the Falklands. A 2013 referendum in the Falklands revealed that 99.8% of the population wanted to remain British. Argentina does not view the people of the Falklands as having a say in the sovereignty of their island, and therefore rejected the vote. They continue to maintain their claim over the Falklands.