The British North Sea, once a hub for oil and gas drilling, has faced a quarter-century of declining production, depriving communities along a foggy stretch of Scottish coastline of their economic core. Now applications for two new offshore drilling projects — a lifeline for the region — could be decided by the government in the coming days. Andy Burnham, Britain's prime minister, faces a choice with complex economic and political ramifications. He could approve the projects — known as Rosebank and Jackdaw — and face a potential revolt from powerful clean energy constituencies that strongly oppose more drilling. Or Mr. Burnham could stop new fossil fuel development in the North Sea and risk sealing the economic fate of the nation's energy heartland.

The drilling plans have been delayed by policy shifts through successive governments, as well as lawsuits. Mr. Burnham has signaled that he may support one or both of the projects. The war in Iran has made imported energy more expensive, giving supporters a potent argument for increasing domestic production. Then there's the Trump factor. President Trump, who mocks climate change and is pushing his fossil fuel agenda on Europe, has pressured Mr. Burnham to open the North Sea. Taylor Rogers, a spokeswoman for Mr. Trump, said new drilling would allow Britain to "restore its energy security and increase global supplies."

Experts say any new drilling can only buy time for Britain's North Sea region. About 93 percent of the basin's oil and gas has already been extracted. Last month, British oil giant BP announced it would put its business there up for sale. In Aberdeen, the epicenter of Britain's drilling industry, local leaders acknowledged the city might never be the energy powerhouse it once was. Rosebank, off the Shetland coast, is Britain's last major developed offshore oil site, with an estimated 300 million to 350 million barrels of recoverable oil. Jackdaw is a gas field east of Aberdeen with an estimated 200 million barrels of oil equivalent.