Atlantic neutrality patrols versus the Pacific war

Could America keep expanding Atlantic neutrality patrols while fighting Japan?

It could, but each Atlantic commitment would withhold scarce ships from the declared Pacific war, making continued expansion difficult to justify.

American destroyers could continue expanding Atlantic neutrality patrols after Pearl Harbor. Every escort retained there would be unavailable for the Pacific campaign, where the United States already faced shortages. A declared war would create stronger pressure for ships than an ostensibly neutral patrol commitment. In this counterfactual, those pressures would favour withdrawing Atlantic forces even if assistance to Britain remained desirable.