Thatcher was challenged for the leadership of the Conservative Party by the little-known backbench MP Sir Anthony Meyer in the 1989 leadership election. Of the 374 Conservative MPs eligible to vote, 314 voted for Thatcher and 33 for Meyer. Her supporters in the party viewed the result as a success, and rejected suggestions that there was discontent within the party.
On December 7, 1989, the Communist Party of Lithuania under the leadership of Algirdas Brazauskas, split from the Communist Party of the Soviet Union and abandoned its claim to have a constitutional "leading role" in politics.
On the morning of 10 December 1989, the first open pro-democracy public demonstration occurred in front of the Youth Cultural Center in Ulaanbaatar. There, Elbegdorj announced the creation of the Mongolian Democratic Union. There the Democratic Union-first pro-democracy movement in Mongolia was born.
Pressure mounted on Bush. Bush declared that the U.S. would not negotiate with a drug trafficker and denied knowledge of Noriega's involvement with the drug trade prior to his February 1988 indictment, although Bush had met with Noriega while Director of the CIA and had been the Chair of the Task Force on Drugs while Vice President. On 15 December, the Panamanian general assembly passed a resolution declaring that a state of war existed between Panama and the United States
The next day after the four U.S. military personnel incident, President Bush ordered the execution of the Panama invasion plan; the military set H-Hour as 0100 on 20 December.
The military incursion into Panama began on 20 December 1989, at 1:00 a.m. local time. The operation involved 27,684 U.S. troops and over 300 aircraft. These aircraft were deployed against the 16,000 members of the PDF.
The Raid at Renacer Prison was an attack on the El Renacer prison in Gamboa, Panama, by units of the 82nd Airborne Division of the US Army on 20 December 1989, during the United States invasion of Panama. During the raid the U.S. military was able to free the sixty-four prisoners held in the detention facility.