In March, Colombian army troops crossed into Ecuador to raid a camp of FARC, the main Marxist group trying to overthrow the Colombian government. Colombian troops killed some guerrillas and high-level insurgent commander Raul Reyes, and captured several laptop computers, which Colombian President Alvaro Uribe said contained proof that the rebels had been in close contact with Venezuelan strongman-President Hugo Chávez.

Now, after an examination of the computers, which Venezuela asserted were planted to discredit it, officials of Interpol and intelligence agencies in the United States and elsewhere say the Colombian charge seems to bear up.

The computer files show that Venezuela has been energetically assisting FARC to obtain arms from foreign suppliers. The arms have been shipped to them through the Venezuelan port of Maracaibo, and $300 million funneled to the rebels to pay for them. The files also detail the pro-FARC involvement of President Rafael Correa, of Ecuador, which had been giving FARC safe haven.

With oil so costly, Venezuela has money to spend on destabilizing the countries around it. Meanwhile, President Chávez continues to see himself as the heir of Fidel Castro, even as his policies, which include nationalization and expropriation, gradually ruin his nation’s economy. For instance, price controls have caused milk and other necessities to disappear from many supermarket shelves.

For the United States, the evidence might suggest to some that it impose sanctions on Mr. Chávez’s regime. The U.S. economic embargo against Cuba has not been a resounding success, and we have long urged that it be dropped.

There are, of course, real differences. Cuba isn’t Venezuela. Still, some sanctions, which could limit the ability of the Venezuelan regime to use international banking systems, among other restrictions, might ultimately make Mr. Chávez more uncomfortable than sanctions ever did Mr. Castro. Everything depends, of course, on how they are structured.

Meanwhile, conserving oil would be a good way to help defang Hugo Chávez.