They were sent in a misguided attempt to prop up the Czarist regime, which was allied with the US against Germany in WW I and was fighting a civil war with the Bolsheviks.
US President Ronald Reagan sent US troops to Beirut, Lebanon on 20 Aug 1982.
President Clinton sent troops to Haiti and Bosnia.
The US.
The obvious answer would be the US and Russia. However, the United States and Russia/Soviet Union have never actually fought each other in a declared war. After the Russian Revolution in 1917, several Western powers tried to reinstate the Monarchy and drive out the Bolsheviks in 1918. Among those who sent troops were the US and Britain. They were unsuccessful. There were also Soviet pilots flying for North Korea as "volunteers" during the Korean War and they undoubtedly engaged American pilots.
US Regulars were sent in '65.
1965
NATO and mostly us troops
I think that the US had already determined to enter the war by the time the Russian Revolution began, so there was little impact. If Russia had withdrawn from the war and the US had NOT entered it, then the outcome might have been different. What many do not know is that the US sent troops to Russia to fight the Bolsheviks. The Americans were sent to Archangel, in northwest region. The British sent troops farther to the east.So, a related question would be: "What impact did USA and Britain have on the Russian Revolution?" For more history on the American expedition to Russia, see: http://bentley.umich.edu/bhl/mhchome/polarb.htm Custermen
They traveled overseas ...
They traveled overseas ...
American Expeditionary Forces under Allied auspices were sent to intervene into the Russian Civil War. The Allied forces implicit objectives were to provide support for the loyalists against the Bolshevik revolutionaries.
Covert only. No conventional combat troops.