The oil crisis of 1973 (also known as the first oil crisis) began on October 16, 1973, following the decision of the Organization of Arab Oil Exporting Countries (which grouped the Arab member countries of OPEC plus Egypt , Syria and Tunisia) with members of the Persian Gulf of OPEC (which included Iran) of not exporting more oil to the countries that had supported Israel during the Yom Kippur War (named after the Jewish commemorative date Yom Kippur), that faced Israel with Syria and Egypt. This measure included the United States and its Western European allies. The increase in price, together with the heavy dependence of the industrialized world on oil, caused a strong inflationary effect and a reduction in the economic activity of the affected countries.