Environmentalists said opening the Atlantic waters would put the coasts of Virginia, the Carolinas and Georgia at risk for an environmental disaster like the BP spill that struck the Gulf Coast in 2010, when millions of barrels of oil washed ashore after the explosion of the Deepwater Horizon rig. Advocacy groups in those states said that the drilling could harm tourism, fishing and other coastal industries that are already major drivers of the Southeastern economy.

But lawmakers from both parties in those coastal states have pushed for years to open their waters for drilling. The Interior Department estimates there are 3.3 billion barrels of recoverable oil on the Atlantic’s outer continental shelf and 31.3 trillion cubic feet of natural gas.

The estimates are based on seismic surveys done in the early 1980s, and energy industry experts say the true reserves may be far higher. In opening up the waters to drilling, coastal states see the opportunity for billions of dollars in new revenue and royalties to flow from oil companies to state coffers, which would help pay for roads and schools and fill in budget shortfalls left by the recession.

For the president, the proposal is a new chapter in his complex and evolving environmental legacy. In announcing the drilling now, he is trying to achieve a balancing act on energy and the environment that he failed to achieve in his first term, in large part because of the BP disaster. Throughout his six years in office, he has tried to push a sweeping, aggressive and controversial plan to fight climate change while offering an appeasement to his opponents in the oil industry and the Republican Party.

“He giveth, and he taketh away,” said Kevin Book, an analyst at Clearview Energy Partners, a Washington analysis firm, of the president’s strategy. “The pairing of environmental policy with energy policy is something that, conceptually, this administration has done since the first term. Sometimes it looks like a balancing act, sometimes it’s serendipitous.”