So, if the world markets gets too dicey, it'd be easy to just cut off the export taps and keep all that oil for Americans, right? Not so fast! First, it's the wrong types of oil in the wrong places. The U.S. doesn't have the infrastructure to transport that domestic oil to where it needs to be, nor the refining capacity to handle it. There's also the pesky issue of enforcing export bans and lower domestic pricing of oil. Go look up Canada's "National Energy Program" from the 80's to see what sort of things might come with that strategy.
If world oil markets go nuts, the U.S. is still very exposed. Putting up a wall would require pipelines and refineries that would take decades to build and policies that could tear apart the country. Americans have a president who is both committed to destabilizing world oil markets and opposing electrification that might reduce the impact of that instability. That's a dangerous combination.