I'd say yes. What they have to remember is
He wants the UN running the whole world, preferably with himself in charge.
The US having an ally in Britain means A: independent nations and B: independent nations working together without being under UN control; neither of which fits into the world he wants.
Add to that the personal grudge he shows against Britain, and the answer is 'Yes'. What makes this funny- in the only way it can be- is you've got one socialist peeing all over another, and Brown's finding he doesn't like it. And it rather causes him some problems.