Operation Nickel Grass was a US military mission to help Israel during the Yom Kippur War in 1973. The Soviet Union helped the Arab Republic of Egypt and the Syrian Arab Republic begin a surprise attack against Israel on October 6, 1973. Between October 14 and November 14 that year, the US flew 22,325 tons of weapons, tanks, and other supplies to Israel in C-141 Starlifter and C-5 Galaxy cargo planes.