1918U.S. Marines occupy Panamanian province of Chiriqui for two years to maintain public order.

1921President Coolidge strongly suggests the overthrow of Guatemalan President Carlos Herrera, in the interests of United Fruit. The Guatemalans comply.

1925U.S. Army troops occupy Panama City to break a rent strike and keep order.

1926Marines, out of Nicaragua for less than a year, occupy the country again, to settle a volatile political situation. Secretary of State Kellogg describes a "Nicaraguan-Mexican-Soviet" conspiracy to inspire a "Mexican-Bolshevist hegemony" within striking distance of the Canal.

"That intervention is not now, never was, and never will be a set policy of the United States is one of the most important facts President-elect Hoover has made clear." --NYT, 1928

1929U.S. establishes a military academy in Nicaragua to train a National Guard as the country's army. Similar forces are trained in Haiti and the Dominican Republic.

"There is no room for any outside influence other than ours in this region. We could not tolerate such a thing without incurring grave risks... Until now Central America has always understood that governments which we recognize and support stay in power, while those which we do not recognize and support fall. Nicaragua has become a test case. It is difficult to see how we can afford to be defeated." --Undersecretary of State Robert Olds

1930 Rafael Leonidas Trujillo emerges from the U.S.-trained National Guard to become dictator of the Dominican Republic.

1932 The U.S. rushes warships to El Salvador in response to a communist-led uprising. President Martínez, however, prefers to put down the rebellion with his own forces, killing over 8000 people (the rebels had killed about 100).

1933 President Roosevelt announces the Good Neighbor policy.

1933Marines finally leave Nicaragua, unable to suppress the guerrilla warfare of General Augusto César Sandino. Anastasio Somoza García becomes the first Nicaraguan commander of the National Guard.

"The Nicaraguans are better fighters than the Haitians, being of Indian blood, and as warriors similar to the aborigines who resisted the advance of civilization in this country." --NYT correspondent Harold Denny

1933 Roosevelt sends warships to Cuba to intimidate Gerardo Machado y Morales, who is massacring the people to put down nationwide strikes and riots. Machado resigns. The first provisional government lasts only 17 days; the second Roosevelt finds too left-wing and refuses to recognize. A pro-Machado counter-coup is put down by Fulgencio Batista, who with Roosevelt's blessing becomes Cuba's new strongman.

1934 Platt Amendment repealed.

1934 Sandino assassinated by agents of Somoza, with U.S. approval. Somoza assumes the presidency of Nicaragua two years later. To block his ascent, Secretary of State Cordell Hull explains, would be to intervene in the internal affairs of Nicaragua.

1936 U.S. relinquishes rights to unilateral intervention in Panama.

1941 Ricardo Adolfo de la Guardia deposes Panamanian president Arias in a military coup-- first clearing it with the U.S. Ambassador.

It was "a great relief to us, because Arias had been very troublesome and very pro-Nazi." --Secretary of War Henry Stimson