Just this week, Latin America's troublemaker-in-chief, Venezuelan President Hugo Chavez, threatened the recently reactivated US Fourth Fleet with two squadrons of newly arrived Russian Su-30 fighter planes, part of a $3 billion arms package he bought in 2006.

Engaging in his unique brand of saber-rattling, Chavez said: "Any gringo ship that sails into brown [i.e., coastal] waters will itself turn brown and go to the bottom, because they'll not get through."

It gets worse.

Clearly not satisfied with the most recent arms delivery, Chavez isn't wasting a minuto building the region's most powerful military in a bid for hegemony, if his late-July visit to Moscow is any sign.

Post-summit reports indicate there might be another $1 billion or so in advanced Russian Tor M-1 air defense systems, T-90 battle tanks and Kilo-class diesel submarines in the pipeline.

But that's only the tip of the arms iceberg: The Russian press is reporting that arms sales to Venezuela over the next 10 years may top another $5 billion, including heavy-lift air transport, air-air refueling tankers (for the fighters) and long-range air-defense systems. Naturally, Chavez insists the buildup is necessary to defend against the US invasion that he's been saying is just around the corner for at least several years now.

Russia is also working with Venezuela on energy projects as the Kremlin looks to gain control over an increasing share of global oil production. This, of course, could lead to a squeeze on the US market, which gets 10 to 15 percent of its oil from Venezuela. In addition to giving the Russians preferential treatment to explore Venezuela's oil-rich Orinoco Belt, Caracas is also collaborating with Moscow to develop an OPEC-like, Russian-led natural-gas cartel.

Venezuela-Iran relations are also troubling. Chavez and Iranian President Mahmoud Ahmadinejad are chummy - and relish the idea of giving US policymakers heartburn when they think of the two states cooperating on missiles or nukes. There are allegations of Venezuelan-Hezbollah ties, too, with Israel insisting that Venezuela has become the largest base for the Iran-backed terror group outside of the Middle East.

Even though he's suffered a string of political setbacks at home recently, Chavez's still scheming to end presidential term limits, nationalize the economy and concentrate political power in Caracas; last week, he secretly approved 26 new laws to do just that, according to press reports. Two weeks ago, El Comandante horrified parents by calling for kids to study Marx's "Communist Manifesto" and emulate revolutionary Che Guevara - all on a day promoting children's welfare in Venezuela.

Fortunately, many Venezuelans are pushing back: They're fed up with high inflation, crime and corruption, especially considering the country's oil and gas wealth - which is often sent abroad to prop up the likes of Cuba.

Despite the shiny new "toys," the military is also none too happy with Chavez's meddling. He's creating militias and politicizing the armed forces, reportedly requiring a Cuban-inspired "Socialism or Death" salute.

And while Colombia is still responsible for 80 percent of the world's cocaine production, efforts under the US-backed "Plan Colombia" are making it tougher for traffickers like the FARC and others. So instead of facing the Colombian police/military, DEA or the US Navy, they're overflying Venezuela en route to Africa and Europe, where cocaine is becoming a big problem. (Chavez refuses to cooperate with US anti-drug efforts.)

Chavez also supports leftist political candidates with "suitcases" of cash, including in Argentina, Mexico, Peru, Bolivia and Nicaragua. He's throwing money at kindred-spirit candidates in El Salvador, too.

So while there's progress here in Colombia, there are still challenges ahead in Latin America - especially in Venezuela, where Chavez's socialist Bolivarian revolution is a growing threat to regional stability and US interests.