Its funny, reading PK Dicks 'The man in the High Castle', in one alternate timeline he writes, Britain and America go to war after WW2. Its not clear why, but presumably the issues of America wanting access to the Imperial market still exist. And that is a problem with the alternate timeline. America wanted markets to dig itself out from the wall street crash. WW2 inevitably dumped them in its lap, but what happens if the 2 Empires still exist and try blocking those pesky American's? I think there would inevitably have been conflict from it. And America would have had less ability to win it, because it never had the excuse of WW2 to rearm.
The last time the US and Britain went to war in 1812 there were more items to compete for and it didn't create long term effects like the creation of Germany did, so just access to market wouldn't be a casus belli.
In fact, without alternate timelines, there was competition between the US and Britain in the ME for example, with the US supporting Saudi Arabia and the British, Iran, to get access to oil.
Just like now, the resource rich countries would sell to whomever had the production plants lined up and would receive goods in exchange, access to the US market would be more important to UK based industry than denying access to India to US goods, so a trade agreement would be hammered out. Protectionism just wasn't good policy: https://microeconomi...s-policy-shift/