Sentence:  To interpret , indeed , the era from 1000 to 800 as a period mainly of consolidation may <WSD>be</WSD> a necessary but unfortunate defect born of our lack of detailed information ; if we could see more deeply , we probably would find many side issues and wrong turnings which came to an end within the period . 
Meaning of the word marked with <WSD> tags:  have the quality of being; (copula, used with an adjective or a predicate noun)