The russians and colombians work hand to hand.. the russians provide colombia with guns while colombia in turn give russia drugs and a pipe line for them to distribute to europe
They all (Russians, Italians, Columbians, Mexicans) work together.
This scenario is straight GTA/ Sons of Anarchy fantasy. If a war would happen the only winners would be law enforcement agencies across the globe.
In real life all these criminal organizations work together and respect each other.(Italian Cosa Nostra were advisors and helped organize both the Russians and the Columbians in the 80s) Why? Because any conflict between them would be mutually assured distruction. Even if one of them could win(and they couldn't), they would lose billions of dollars, get huge LE heat and ultimately be destroyed.
While internal disputes may happen(i.e. Italians vs Italians), you'll never see violence between different ethnic Mafias. Organized crime is one of the most globalized "industries" on the planet. All these organizations rely on each other for drugs, guns, money laundering services etc.