On Oct. 17, 1973, Arab oil producers moved to cut oil supplies to the United States and other countries that backed Israel in the Yom Kippur War, according to HISTORY and C-SPAN Classroom. HISTORY reported that exports were to be cut by 5% every month until Israel left the lands it had occupied in the 1967 war.

A CIA memo from the time, published by the State Department's Office of the Historian, records that the Oct. 17 decision was made by the Organization of Arab Petroleum Exporting Countries, or OAPEC. It says the Arab producers would cut production by at least 5% a month and threatened a total embargo of countries that used their armed forces to aid Israel.

By Oct. 19, several Arab producers, including Saudi Arabia, Kuwait, Libya and Abu Dhabi, had announced or threatened a total embargo against the United States, according to the same CIA memo, which is dated that day.

Egypt and Syria had attacked Israel earlier that month, and Israel had pushed back with the help of a U.S. airlift of arms, HISTORY reported. Oil prices eventually quadrupled, bringing price gouging, gas shortages and rationing to the United States and Europe, HISTORY reported. The embargo led to gas lines and a massive oil shortage in the United States, C-SPAN Classroom reported. It also led to energy policies such as a ban on U.S. oil exports that ended in 2015, C-SPAN Classroom reported.

The embargo against the United States was lifted in March 1974, HISTORY reported. The prospect of a negotiated end to fighting between Israel and Syria helped persuade the producers to lift it, according to the State Department's Office of the Historian. Oil prices stayed well above their mid-1973 level, and by 1980 crude cost 10 times what it had in 1973, HISTORY reported.

What we know: Arab oil producers moved against Israel's backers on Oct. 17, 1973, and several had announced or threatened a total embargo of the United States within two days.
What we don't: These sources do not say how much oil each Arab producer actually cut in the first months.