Great minds think alike. I just sent a similar scenario to Dogsoldier.
Irish terrorists in Colombia kidnap the US, British and German ambassadors from their respective consulates. The three countries ask for US Marines to rescue the hostages, thoroughly insulting the Colombians who retaliate by blocking off the town. The Marines must rescue the hostages AND get past the Colombian Army. Their only assistance is a small DSS contingent from the US consulate, unless they can rescue the hostages safely and get them to their rally point. If they can, then the IRA players become Army Rangers and help the Marines get through the Colombian cordon.