Former UK Prime Minister Boris Johnson has alleged that Russian President Vladimir Putin “must have killed” Wagner boss, Yevgeny Prigozhin, and that there can be no peace negotiation with Putin on Ukraine.   Writing in a Daily Mail op-ed on Saturday, August 27, Johnson speculated about Prigozhin’s last moments, just days after a plane believed to be carrying the Wagner boss crashed in a field northwest of Moscow while en route to St. Petersburg. The ex-British PM claimed that …