The Wild Geese - 1978

A company that is multi national seeks to overthrow a vicious dictator. It hires a band of (largely aged) mercenaries in London and sends them into rescue the virtuous but imprisoned opposition leader who is also critically ill and due for implementation. Just when a rescue that is ideal has been performed by the team, the multi national does a deal with the barbarous dictator leaving the mercenary band to escape their own steam and exact revenge.