Oil barely garnered a mention from U.S. President Donald Trump during his glitzy visit to Saudi Arabia this week. But the black gold may explain why the trip went so smoothly.

Saudi government officials ”haven’t said they’re going to crush the U.S. oil and gas industry, but it’s a foregone conclusion,” Sankey said in an interview. Meanwhile, “low oil prices is one of the things [Trump] can point to as a promise delivered.”

Since he returned to the Oval Office, the benchmark West Texas Intermediate oil price has fallen from $80 a barrel to $60 (see chart 1). That is a problem for the country’s shale patch, which accounts for around two-thirds of domestic output—and for smaller producers in particular,