The recent tit-for-tat episode between Venezuela and Colombia brought to the forefront the military capabilities of both countries.
Each side as their strengths and weaknesses. Venezuela has far less troops than Colombia, and Venezuelan troops aren't well trained. On the other hand, Venezuela has more fire power (more artillery, bigger and better aircraft, and tanks). The Colombian Army doesn't have tanks due to the nature of where they operate: mainly in the Andes mountains and jungles, neither place conducive to using tanks, but has been engaged in an on-going war with the likes of the FARC and ELN for the past 40 years. Venezuelan troops have been acting in more humanitarian capacity (by design).
Venezuela is gearing up a militia to defend the homeland in case of an invasion. If you believe Chavez' rhetoric, the US is just chomping on the bit to come and invade his country. As the article also points out, this militia acts as means to rescue Chavez in case of another attempted coup; the last one supported by commanding officers in Venezuela's military.
I would agree with the first article's assessment that Chavez wouldn't be the one to push Venezuela into a war. While he isn't the brightest bulb in the bunch, he's not stupid enough to go against a military force that is bigger and better prepared than his.
The real concern with the ramping up of militias in Venezuela is what will happen when Chavez is defeated in the next election. While that election is in 2012, events may transpire between now and then that bring about the fall of Mr. Chavez term as president. While Chavez' popularity is on the decline in Venezuela, there remains a small stalwart segment of supporters (those that Chavez was supposed to help, but who aren't much better off now than they were before other than they now have weapons to help them express their pent up anger) ready to defend him and fight for him.
At that point, the concern would be that these civilian militias step in, and all out civil war will ensue. That's the point at which the world will find out where the loyalties of the Venezuelan army lie, and if the opposition to Chavez has been able to arm itself as well.
So the powder keg is really Venezuela itself and it's being fueled by petrodollars, and Chavez rhetoric.