CAMBRIDGE – When President Richard Nixon proclaimed in the early 1970’s that he wanted to secure national energy independence, the United States imported a quarter of its oil. By the decade’s end, after an Arab oil embargo and the Iranian Revolution, domestic production was in decline, Americans were importing half their petroleum needs at 15 times the price, and it was widely believed that the country was running out of natural gas.
美国剑桥—20世纪70年代初，在尼克松总统表示希望能够保证国家能源独立的时候，美国有四分之一的原油需要进口。20世纪70年代末，在经历了阿拉伯石油禁运和伊朗革命以及国内石油产量的下跌后，美国原油进口比例上升到了50%，而油价上涨了15倍。当是时，人们相信美国的天然气很快就要开采殆尽了。