Complex sentence: The United Kingdom employed nuclear-powered submarines against Argentina during the 1982 Falklands War; the sinking of the cruiser ARA "General Belgrano" by HMS "Conqueror" was the first sinking by a nuclear-powered submarine in war.
Split into simpler sentences: The United Kingdom employed nuclear-powered submarines against Argentina during the 1982 Falklands War. The sinking of the cruiser ARA "General Belgrano" by HMS "Conqueror" was the first sinking by a nuclear-powered submarine in war.