<prompt> Translate the following text to EnglishKwa mtazamo wa nyuma, Solidarity ilikuwa muhimu katika kuanzisha misingi ya upinzani kwa utawala wa Kikomunisti katika Ulaya ya Kati na Mashariki.  <response>: Viewed from hindsight, Solidarity was critical in establishing the foundations for opposition to Communist rule across Central and Eastern Europe. 