Task: Question Generation
Input (English): In 1964, Turkey tried to invade Cyprus in response to the continuing Cypriot intercommunal violence. But Turkey was stopped by a strongly worded telegram from the US President Lyndon B. Johnson on 5 June, warning that the US would not stand beside Turkey in case of a consequential Soviet invasion of Turkish territory. Meanwhile, by 1964, enosis was a Greek policy that could not be abandoned; Makarios and the Greek prime minister Georgios Papandreou agreed that enosis should be the ultimate aim and King Constantine wished Cyprus "a speedy union with the mother country". Greece dispatched 10,000 troops to Cyprus to counter a possible Turkish invasion.
Output (English): Which US President prevented Turkey from invading Cyprus?