In 1955 and 1958, mainland China escalated Cold War political tensions by shelling nearby islands from Xiamen in what became known as the First and Second Taiwan Strait Crisis. The Nationalists responded by reinforcing Kinmen and shelling Xiamen. The Gaoji Causeway built from 1955 to 1957 notionally transformed Xiamen Island into a peninsula, and so it was termed in the heady propaganda of the time. Due to political tensions, the eastern half of Xiamen Island and much of the Fujian Coast facing the offshore islands remained undeveloped in the 1960s and 1970s. The Water Police and Post-Office were situated directly across the water from the American embassy.