Chris Gavin writes for National Review Online about relations between the United States and United Kingdom after Brexit.

With less than 90 days left until the United Kingdom is set to leave the EU, Prime Minister Boris Johnson has staked his new premiership on a “do or die” Brexit by October 31. Foreign Secretary Dominic Raab and Trade Secretary Liz Truss are crisscrossing North America as part of Downing Street’s latest push to shore up economic and political ties with key allies ahead of the looming withdrawal deadline. The United States will play a particularly important role for post-Brexit Britain regarding everything from trade to defense relations. Thus, London’s latest overtures to Washington are hugely significant for ensuring an orderly Brexit — deal or no deal.

Despite the importance of presidential–prime ministerial ties for the strength of Anglo–American relations, Congress remains the crucial player when it comes to any sort of free-trade agreement. Article I, Section 8 of the U.S. Constitution gives Congress the ability to regulate commerce with foreign countries, and both chambers of Congress must approve any trade agreement that the president has introduced.

Like much in Washington today, Congress remains divided on the possibility of a U.S.–U.K. free-trade deal, particularly over the question of Northern Ireland. …

… In contrast to the House’s approach, Senator Tom Cotton (R., Ark.) and 44 other Republican senators recently penned a letter to the prime minister, voicing their commitment to intelligence sharing and trade relations, as well as “continued, unwavering support for the special relationship between our two countries as Britain leaves the European Union.”