There are only two logical scenarios in which a serious war would develop between Venezuela and Colombia (as opposed to localized border skirmishings in order to create noise on the nightly news). The first would be a U.S.-led invasion in order to overthrow the Chávez government. This is unlikely in the forseeable future due to U.S. imperial overstretch.
The second would be a Venezuelan invasion of Colombia, which would probably only take place in after some major, world-shaking event which would guarantee that the U.S. would not be able to effectively intervene for at least a couple of months.
This is what we will presume happens for our scenario purposes...
On September 11th 2012, three nuclear devices are detonated on U.S. soil, one each in New York City, Washington D.C. and Los Angeles. The U.S. is thrown into chaos precisely at a time when Colombia and Venezuela have upped their saber-rattling to new heights. With the Venezuelan military already completely mobilized, Hugo Chávez sees a window of opportunity and gives the green light for long-prepared invasion plans.
Even an ego as big as Hugo's, however, realizes that Venezuela will not be able to completely conquer and occupy Colombia, at least not over the short term. The upcoming offensive is thus designed to seize the northern border region between the two countries - precisely that area where a large part of Colombia's energy extraction infrastructure is located. Chávez believes that a successful Venezuelan blitzkrieg will be seen as a fait accompli by most of the west and is prepared to "magnanimously" withdraw the Venezuelan Army (after it's caused as much damage as possible) if he encounters serious diplomatic danger. Hugo hopes that such a victory will present the FARC and its allies with a golden opportunity to fatally destabilize the nation's government, bringing another Bolivarist state into being in South America.
The border between Colombia and Venezuela is a difficult one for offensive military operations. From the Caribbean coast on down to the Rio Arauca (about halfway along the border), Colombia’s three northern frontier provinces of La Guajira, Cesar and Norte de Santander are shielded by the northern extension of the Andes. From the Arauca on south, the frontier is covered by an almost completely trackless stretch of the Amazon rainforest.
The frontier is crossed by few paved roads, the main ones cutting through the mountainous Norte de Santander province at Cucutá. Though much ink has recently been spilled over Venezuela’s purchase of modern T-72 tanks and BMP-3 AFVs, it’s quite obvious that these weapons systems are less than ideal for use in the mountains and jungle which cover most of the Colombian-Venezuelan border.
Given the above, practically the only viable route for a conventional armored thrust out of Venezuela is along the extreme north of the frontier, out of the Maracaibo Basin and across the base of Colombia’s northernmost peninsula, with the attacker’s right sleeve practically brushing the Caribbean. Even this route is problematic, however, for once across the peninsula, the attacker faces the Sierra Nevada de Santa Marta – a mountainous region which blocks off any further advance to the direct west.
At this point, a putative Venezuelan armored offensive has only one viable route: over the foothills surrounding the El Cerrejón open-face coal mine and southwest into the Upar Valley. The immediate objective of a strike in this direction would be to take Valledupar, the capital of Cesar Province, thus opening a route into Colombia’s low-lying Caribbean coastal region. An equally important objective would be securing the peninsular region and the Sierra Nevada against Colombian counterattacks in order to maintain a land supply line back to Venezuela. A successful operation of this sort would probably be followed up by a strike southeast into Norte de Santander province, in conjunction with infantry attacks out of the Maracaibo Basin, in order to open up the Cucutá highways as supply routes.
Phases one, two and three of a possible Venezuelan offensive operation through the Upar Valley.
Colombia apparently is aware of the threat of a strike of this sort as it is opening a new military base in an undisclosed part of Guajira Province. One would assume that this base will be located near the provincial capital of Riohacha. Still, it would seem that Colombia’s chances of stopping an armored thrust into Guajira short of El Cerrejón would be slight, given that Venezuela would have the initiative. But El Cerrejón poses a very interesting bottleneck which is potentially fatal to any Venezuelan offensive…
The northern access to the Upar Valley. Venezuelan forces would be entering this map down Route 88 from the NE, moving towards Hato Nuevo in the SW. The El Cerrejón coal mine is situated at Point A.
El Cerrejón is a open-pit coal mining complex: one of the largest in the world. Its operations close off the only relatively flat entrance into the Upar Valley. To the immediate east of the mine, Route 88 (which would have to be Venezuela’s primary supply route by default), winds through a narrow defile before opening out into the mining town of Hato Nuevo. In my opinion, this would be the region in which Colombia’s First Division would attempt to block the mechanized forces of the Venezuelan Fourth Armored Division.
Two views of El Cerrejón. Those things that look like 1/600 Tonka Toys are actually 154 ton-capacity Wabco haulers. I think we can agree that even Ogres would have difficulties tackling those slopes...
Operationally, Colombian armored cavalry and infantry would be looking to delay attackers in the El Cerrejón region while Colombia’s rapid deployment force (made up of several battalions of elite paratroopers supported by 120 Blackhawk helicopters) would prepare to counterattack along the thrust’s western flank. Meanwhile, Venezuela would be seeking to push through El Cerrejón at all possible speed. The terrain is not conducive to airborne operations, but Colombian airmobile forces would probably be deployed here on the first day in an attempt to seize and hold the mines and the Route 88 bottleneck for the follow-on armored forces. Obviously, 42nd Para Battalion would be the force most likely chosen for this attack, given that it’s an elite force integrated into the Venezuelan 4th Division – the operational unit which contains most of Hugo Chavez’ new armored toys.
Given this, our first scenario will represent an attack into the El Cerrejón mining complex by Venezuelan paratroopers, backed up by light armored units from the 44th Light Armored Brigade.