In order for the united states to build the panama canal, it first had to rebels defeat this nation.

Colombia.

Previously, Panama was part of Colombia, which denied the Canal that would cross the country as a commercial route proposed by the United States, because of this, the insurgent population of Panama or "rebels" were the US army to defeat the Colombian nation Satisfactorily, and establish Panamanian independence, which would consequently yield the fruit of the Panama Canal.