HOUSTON — When OPEC barred oil exports to the United States in 1973, creating long gasoline lines, President Richard Nixon pledged an effort that would combine the spirit of the Apollo program and the determination of the Manhattan Project.“By the end of this decade, we will have developed the potential to meet our own energy needs without depending on any foreign energy sources,” he said in a televised address.His timing was off — it took more than 40 years — but the country has come pretty close to energy independence in recent years thanks to a surge in domestic shale oil and natural …
