From Longman Dictionary of Contemporary Englishby/through force of circumstance(s)by/through force of circumstance(s)British EnglishEFFECT/INFLUENCE if something happens by force of circumstance, events outside your control make it happen → force
Examples from the Corpus
by/through force of circumstance(s)• Like all Trolls they will eat anything and through force of circumstance they tend to eat a lot of rocks.• Some sectors, moreover, lagged behind completely, by force of circumstances or on account of reluctance to abandon traditional ways.• Ware was a strict Palladian by upbringing but a stylistic schizoid by force of circumstances. 