Complex sentence: Cuba sent troops to fight against Israel during the War of Attrition, and also joined the expeditionary forces during the 1973 Yom Kippur War, and broke diplomatic relations with Israel the same year.
Split into simpler sentences: Cuba sent troops to fight against Israel during the War of Attrition. Cuba also joined the expeditionary forces during the 1973 Yom Kippur War, and broke diplomatic relations with Israel the same year.