BALTIMORE — THE Obama administration’s whiplash decision last week to allow oil and gas companies to drill along a wide area of the Atlantic Coast is a big mistake.

The facts support a ban on offshore drilling not only in the wilds of Alaska — as the administration has announced — but also along our densely populated, economically vibrant and environmentally diverse Eastern Seaboard.

The BP Deepwater Horizon disaster should remind us that the benefits of drilling do not outweigh the threat to local economies, public health and the environment when an inevitable spill occurs. The spill, occurring off the Louisiana coast less than five years ago, devastated the Gulf of Mexico region — most likely costing over $100 billion in lost economic activity and restoration expenses, disrupting or destroying hundreds of thousands of jobs and causing long-term damage to 3,000 miles of fragile wetlands and beaches. Experts estimate that only 5 percent of the 4.2 million barrels of oil spilled in the gulf was removed during the cleanup; even today, oil from the spill is still appearing on the white sand beaches of the Florida Panhandle.

To allow drilling off the Atlantic Coast is to willfully forget Deepwater’s awful lesson even as the economic, environmental and public health consequences continue to reverberate in communities along the gulf. If a disaster of Deepwater’s scale occurred off the Chesapeake Bay, it would stretch from Richmond to Atlantic City, with states and communities with no say in drilling decisions bearing the consequences. The 50-mile buffer the administration has proposed would be irrelevant. And unlike the gulf, the Chesapeake is a tidal estuary, meaning that oil would remain in the environment for decades.