From one of the lists, post-WWII to the beginning of Vietnam:
1946 Iran Troops deployed in northern province.
1946-1949 China Major US army presence of about 100,000 troops, fighting, training and advising local combatants.
1947-1949 Greece US forces wage a 3-year counterinsurgency campaign.
1948 Italy Heavy CIA involvement in national elections.
1948-1954 Philippines Commando operations, "secret" CIA war.
1950-1953 Korea Major forces engaged in war in Korean peninsula.
1953 Iran CIA overthrows government of Prime Minister Mohammed Mossadegh.
1954 Vietnam Financial and materiel support for colonial French military operations, leads eventually to direct US military involvement.
1954 Guatemala CIA overthrows the government of President Jacobo Arbenz Guzman.
1958 Lebanon US marines and army units totaling 14,000 land.
1958 Panama Clashes between US forces in Canal Zone and local citizens.
1959 Haiti Marines land.
1960 Congo CIA-backed overthrow and assassination of Prime Minister Patrice Lumumba.
1960-1964 Vietnam Gradual introduction of military advisors and special forces.