By PHIL GUNSON AND PABLO BACHELET

Colombia's military recently had one of its defining moments in a raid that killed a senior leader of the FARC, a resilient guerrilla group that had never before lost a member of its top leadership in combat.

At about the same time, U.S. officials and military analysts say, Venezuela fumbled an effort to rush troops and tanks to the border with Colombia in response to Colombia's deadly March 1 attack on a FARC camp in Ecuador.

The Colombian raid triggered a mostly diplomatic and short-lived crisis. But it also showed the contrasting security philosophies of Venezuela's socialist President Hugo Chávez and Colombia's conservative President Alvaro Uribe.

Colombia, with U.S. help, has assembled a nimble infantry-based and intelligence-reliant counterinsurgency force capable of striking at guerrilla units and leaders deep in the jungle, military analysts say.

The Venezuelans have done just the opposite: They have spurned all contacts with the U.S. military and instead opted mostly for big-ticket purchases of Russian fighters, attack helicopters and submarines while also forming, training and arming reserve and militia units loyal to Chávez.

The result is that Venezuela's military is impressive on paper but also in many ways a paper tiger, according to defense experts, shaped more to preserve Chávez's grip on power than to fight an effective war.

Colombia, said John Cope, with the Institute for National Strategic Studies of the National Defense University, has become ''an extremely good, professional force,'' while the Venezuelan army is ``trying to figure out the ins and outs of an approach to a military organization that puts a high emphasis on civic action and humanitarian issues . . . which means they're probably not spending an awful lot of time training.''

The contrast of the two militaries is more than an academic exercise. Few analysts believe Chávez, a fiery critic of U.S. policies, would ever provoke a war against Uribe, a stalwart Washington ally. But U.S. officials say that with the border environment still combustible given the presence of the FARC, even a minor provocation could escalate into a military conflict.

BOGOTA'S TIES TO U.S.

In sheer manpower, Colombia has an edge. Jane's Sentinel Security Assessment places the Colombian armed forces, not including the sizable police force, at 263,000, more than double Venezuela's 115,000.

Colombia's forces are modeled on the U.S. military, with seven army divisions, three naval units and eight air commands coordinated by five geographically based joint commands. According to Jane's, the idea is to ensure closer cooperation between the different branches of the military.

In a process that began before Uribe took office in 2002, the Colombian military has shifted its focus on counterinsurgency and counter-drug-trafficking, putting together helicopter-based and other highly mobile battalions and special forces units.

Many of the units have been trained by the 500 or so U.S. advisors in the country with part of the estimated $600 million in military aid that Washington provides annually to Colombia. The United States has supplied more than 100 aircraft, including 24 UH-60 Black Hawk helicopters and more than 60 Huey II helicopters.

Colombian and U.S. officers also maintain a Joint Intelligence Center in the southern base of Tres Esquinas, which gathers information from communications intercepts and images from U.S. spy planes, listening stations and satellites, according to Jane's.

True to its counterinsurgency strategy and its partly mountainous, partly jungled terrain, Colombia has no combat tanks.

VENEZUELA'S TACK

In contrast, Chávez has severed all military ties with the United States, which in turn has stopped selling him weapons and replacement parts.

Chávez has promoted the concept of asymmetrical warfare -- essentially preparing reserves and militias for a guerrilla war against a stronger invader, presumably U.S. troops.

But his regular armed forces are regarded as logistically challenged, and U.S. officials believe the army struggled to move several tank units toward the Colombian border after Chávez gave the order on March 2. Venezuela has nearly 200 tanks.

There are also doubts about the military's equipment maintenance. A foreign military officer who asked not to be identified because of the sensitivity of his job said the gun-sights on some of the tanks had been rendered inoperable by attempts to service them without help from foreign technicians.

''It's all image,'' said Cope, who added that Chávez seems more interested in reorganizing the military so it is less of a threat to him. Chávez survived a brief military coup against him in 2002.

The growing militia units can quickly mobilize to defend his government should the regular military turn against him, Cope added, and Chávez has pulled together the better-trained units from all branches under one ``operational strategic command.''

''This responds more directly to him, personally, '' Cope said. ``And this is probably the group that does have some training.''

AIR FORCES COMPARED

Military analysts believe Venezuela has a big edge over Colombia in the air, given recent purchases like 10 Russian-made Mi-35 'flying tank' attack helicopters that can carry eight soldiers and have both anti-tank and air-to-air capacity.

Right after ordering troops and tanks to the Colombian border, Chávez also threatened Uribe with ''sending over the Sukhois'' -- advanced Russian fighter-bombers that make the Colombians' aged French Mirages and Israeli Kfirs look puny.

Colombia recently acquired 15 155 mm cannons from Spain to offset a perceived Venezuelan artillery advantage. And in February, it spent $200 million to purchase 24 newer Kfir C10 fighters, which are yet to be delivered.

Colombia's Cessna A-37B Drangonflies and Brazilian Super Tucano turboprops, which bombed the camp in Ecuador with lethal accuracy, would be blasted out of the sky by the two-dozen Sukhoi Su-30s purchased by Chávez, though Venezuela's pilots are still reported to be training to fly them.

PUBLIC OPINION COUNTS

The greatest doubts concern Venezuela's readiness for war and the willingness of the civilian population to endure hostilities. Unlike Colombia, which has been embroiled in conflict with a domestic guerrilla movement for decades, Venezuela hasn't fought a war for over a century.

''These days, public opinion has considerable weight,'' he Gen. Raúl Salazar, who was Chávez's first defense minister and later his ambassador to Madrid. ``You can't go to war without the consent of the population.''

Miami Herald staff writer Carol Rosenberg contributed to this report from Miami and special correspondent Phil Gunson contributed from Caracas.