Complex sentence: It took some time before the MIR finally could achieve its ultimate identification as a solely Marxist-Leninist political organization, and this was the work of Miguel Enríquez for the two years to come.
Split into simpler sentences: It took some time before the MIR finally could achieve its ultimate identification as a solely Marxist-Leninist political organization. And this was the work of Miguel Enríquez for the two years to come.