Janissaries by Jerry Pournelle
Paperback. Condition: Good. 1986. ACE.
Book #1 in the Janissaries series.
Captain Rick Galloway and his men had been talked into volunteering for a dangerous mission--inly to be ruthlessly abandoned when faceless CIA higher-ups pulled the plug on the operation. They were cut off in hostile territory, with local troops and their Cuban "advisors" rapidly closing in. And then the alien spacceship landed.