Sentence:  Unlike the decline of British hegemony, in the current world-system no military or economic contender has emerged to replace US hegemony. Even though the US SCA has entered its <WSD>autumn</WSD> with the Vietname War and the economic crisis of the mid-1970s, there has been no legitimate hegemonic contender capable of instituting a new global regime to resolve both social and economic contradictions of global capitalism. 
Meaning of the word marked with <WSD> tags:  (by extension) The time period when someone or something is past its prime.