Foxwood Farm represents the British Empire, presided over by the benevolent gentleman-farmer Mr. Pilkington. He represents not just the Empire, but the West in general, including the United States. Although Napoleon is initially opposed to Pilkington, seeing him as a representative of the hated human oppressor, he eventually develops an understanding with him, in much the same way that the Soviet Union under Stalin came to a modus vivendi (mode of living) with the Western capitalist powers.

This is what Orwell is referring to in the famous last line of Animal Farm:

The creatures outside looked from pig to man, and from man to pig, and from pig to man again; but already it was impossible to say which was which.

Under Napoleon, the pigs have become almost indistinguishable from humans, just as Soviet Communists became every bit as greedy, rapacious, and as imperialistic as their Western rivals. The change of name from Animal Farm back to Manor Farm is crucial here; Animal Farm is no longer a living embodiment of Animalism but a pale shadow of human-run farms such as Foxwood.