The relationship between the British and the German-Austrian alliance is not that bad, which might be the only alliance the UK is likely to join.
Historically, it was indeed like this; at the end of the 19th century, the British nearly reached an alliance treaty with the Germans. If such a treaty could have been achieved, the outcome of World War I would have changed significantly.
Unfortunately, the British Prime Minister Robert Gascoyne-Cecil, who adhered to conservatism and isolationism, strongly opposed Joseph Chamberlain's proposal to ally with the German Empire, ultimately causing the potential Anglo-German alliance to miscarry.
Of course, the Chamberlain mentioned here is not the British Prime Minister Arthur Neville Chamberlain, who later advocated appeasement policies during World War II, but his father, Joseph Chamberlain.
