For this day he shall forgive you, to purify you, that you be cleansed from all your sins. Yom Kippur " The day of Atonement", is one of the holiest days in the Judaism calendar. It's celebrated for 26 hours, the 10th day of Tishrei (in 2018, from several minutes before sunset on Tuesday, September 18, until after nightfall on Wednesday, September 19).
This article is not about "how to celebrate Yom Kippur", this article is about the year of 1973, when Egypt and Syria launched a coordinated attack against Israel on Yom Kippur, the holiest day celebrated in Jewish culture.
The idea was, as the city will be in the mood of celebration and there would be no government delegates on work, as per rituals.
Egypt and Syria will join the celebration with Soviet weapons. Attacking Israel from two ends, North and South.
6th October 1973
The purpose of this attack was established 6 years before during the 6-day war of 1967, where Israel captured Palestine, as well as the Egyptian Sinai desert, and the Golan Heights from Syria.
In the hope to reoccupy the lost land, Egypt and Syria launched the attack. A week into the attack, Israeli forces mobilized themselves and retaliated. Which looked like a victory for the Arab countries, turned out in the favor of Israeli's.
Israeli forces continued attacking and advancing to within 30 km of Damascus(Capital of Syria) and occupying new territories.
Simultaneously both the USSR and America kept on providing arms and remuneration to their allies.
15th October'73
Israeli counterattack turned the war into their side, in the fear of losing the capital Cairo(Capital of Egypt) and Damascus(capital of Syria), the Arab countries decided to use a different strategy- Oil. The Arab oil-producing countries, under the Organisation of Petroleum Exporting Countries (OPEC), decided to reduce their oil production by five percent(aljazeera.com) and keep it like that for every month till Israeli forces withdraw from Arab territories occupied by them during the war of 1967.
The Arab countries also enforced a ban on supplying Oil to US (ally to Israel).
The ban resulted in major price hikes all over the world. After this US stopped supporting the war.
October ended with a ceasefire deal between both the nations at war. In the end, roughly Israeli lost 3000 soldiers, whereas Syria and Egypt lost 10000 soldiers combined.
Finally, on 22nd October, the UN Security Council announced the passing of Resolution 338, which stated Israel to withdraw from the territories it occupied in 1967.