The phrase "to break the strike" refers to the act of stopping or preventing a strike from continuing. It typically involves actions taken by employers or authorities to get workers to stop striking and return to work. Full definition
It has been argued that blacks have been historically recruited in the south to break strikes in what is now called the rust belt. (politics.stackexchange.com)
The #DeleteUber campaign, which was sparked by a misinterpreted attempt to break a strike by New York City cabbies, caught on because there had already been so much anger simmering against the ride - hailing company. (hanfordsentinel.com)
The FBU have also said their members will be free to break the strike if a «major incident» takes place. (politics.co.uk)