"Former ally" refers to a person, group, or country that used to be an ally but is no longer. Some synonyms for this phrase include "former accomplice," "one-time partner," "ex-collaborator," "past comrade," "erstwhile friend," or "former confederate." These words can be used interchangeably to describe a partner who has since become an opponent or an adversary. In politics or international relations, the phrase "former ally" carries significant weight as it suggests a shift in policy or a change in strategic interests. Nevertheless, these synonyms allow for a more versatile way to describe a now-disavowed partner.