President Joe Biden’s administration has contemplated the lifting of sanctions on Belarusian dictator Alexander Lukashenko’s regime in a bid to secure the export of Ukrainian grain without risking the maritime confrontation with Russia that some other allies deem necessary to avert a horrific famine. U.S. officials have broached the Belarus idea with European officials in recent weeks, as trans-Atlantic policymakers endeavor to escape a dilemma created by Russia’s blockade of Ukraine’s ports on the Black Sea. Yet other members of NATO have a growing interest in a maritime operation to challenge that blockade, given the limited amount of grain that...