Chomsky today, of course, is not the Chomsky of the 1970s. While he remains an opponent of US imperialism and a critic of some Israeli policies, his position is less than radical on a number of questions.
In the last decade, he has vociferously and actively opposed the boycott, divestment and sanctions (BDS) movement’s call to boycott Israel, though he supports boycotting Israeli settlement goods. In addition, and this is most relevant today, he has always been an anti-Soviet cold warrior, even at the height of his anti-US imperialism (anti-Sovietism, and today anti-Russianism, has always been endemic to the US liberal and socialist left).
Chomsky’s anti-imperialist political commitments never relied on any explicit or accepted theory of the nature of imperialism as based on capitalist economic exploitation, which is why he often casually accused the Soviets of also being an “empire”. That he is a signatory to a letter that accuses opponents of US and NATO intervention in Syria of being apologists for Assad has clearly transitioned him to the very same position his enemies occupied when they called him an apologist for the Khmer Rouge.