According to Wikipedia, they used the trident, which dates back to the Kievan Rus, "to demonstrate the continuity and interrelatedness of Russian and Ukrainian tradition". They made a big deal of presenting an inclusive image in regards to ethnic minorities.

There's also this:

William Blum has claimed in "Killing Hope" that the CIA worked with the Russian exile anti-communist group National Alliance of Russian Solidarists (NTS) in covert operations inside the Soviet Union. Blum claims the CIA covertly trained, equipped, armed and financed the NTS out of West Germany and secretly dropped their operatives as paratroopers into Soviet territory. From there, Blum claims these groups engaged in actions such as assassinations, stealing documents, derailing trains, wrecking bridges and sabotaging power plants and weapons factories. The Soviet Union claimed it caught about two dozen of these operatives, including a former Nazi collaborator, and subsequently had them executed.