Why Did the U.S. Send Only 3000 Troops to Counter Russia in Ukraine? A Game Theory 101 Investigation

Due to the recent events in Ukraine, the United States mobilized about 3000 soldiers, sending them to Poland and Romania. They pale in comparison to the estimated 130,000 soldiers Russia has lined up around Ukraine. If Russia were to use Ukraine as a stepping stone to move further west, the 3000 troops would stand no chance. So why didn't the U.S. send more?

The answer is tripwires. Those soldiers will be the first casualties of war, and force the United States to respond. Internalizing the credible threat of retribution, Russia would not want to advance any further.

This video describes how tripwire mechanisms work, discussing a historical example of West Berlin during the Cold War and connecting the idea to modern-day crisis bargaining theory.