A Venezuelan National Guard sergeant looks across the Táchira River that marks the Venezuelan-Colombian border. On the other shore, a man on a bicycle is shaking his fist and shouting: "You are going to kill us all from hunger. Let us work!"

The sergeant shrugs and returns to his border outpost under a shade tree.

Venezuelan President Hugo Chávez has ordered the National Guard to crack down on the smuggling from Venezuela to Colombia where food and fuel fetch prices at least twice as high. Thousands of people along the 1,300-mile border live off the illegal trade.

But the anger expressed by the man on the bicycle reflects a broader tension building between Bogotá and Caracas that some analysts say is being stoked by Mr. Chávez to deflect attention from problems at home.

This past Friday, Chávez said that Colombia and the United States are plotting a military "aggression." He cited recent visits to Colombia by US Secretary of State Condoleezza Rice; US Adm. Mike Mullen, chairman of the Joint Chiefs of Staff; and the head of the US Southern Command, Adm. James Stavridis.

"I accuse the government of Colombia of designing a conspiracy, a war provocation against Venezuela, following orders from the US ... that could spark a war," Chávez said.

But Colombians say it is Chávez who wants to spark a conflict.

Over the weekend, Chávez called on Cuba, Bolivia, and Nicaragua to form a military alliance against attacks by the US. A day later Nicaraguan President Daniel Ortega accused Colombia of stepping up military operations around Colombian islands in the western Caribbean claimed by Nicaragua.

The Colombian foreign ministry issued a statement Monday saying: "Colombia has never been, nor will it be, an aggressor country."

Colombian defense analyst Alfredo Rangel says that what he calls Chávez's "verbal incontinence" is just an attempt to deflect attention from an increasingly critical economic situation in Venezuela and recent setbacks suffered by Chávez. "You can't confuse a temper tantrum with a war," he says.

Venezuela's inflation soared to 22.5 percent last year, the highest rate in Latin America, while at the same time food staples have become scarce. Government price controls on basic goods such as milk, sugar, cooking oil, and toilet paper that began in 2003 have discouraged production and encouraged speculation. To avoid selling at a loss, many Venezuelan firms smuggle products to neighboring countries.

Last week, Chávez ordered the redeployment of 1,200 National Guard troops already on the border to engage in "Operation Sovereign Homeland," an anticontraband mission. Chávez warned that if the National Guard couldn't do the job, he'd send in the Army.

The pragmatic friendship that had ruled relations between the leftist Chávez and Colombia's conservative, pro-US president, Alvaro Uribe, broke down in November. Mr. Uribe withdrew his support of the Venezuelan leader's mediation efforts with the FARC, the leftist rebels who are holding some 44 hostages, including three Americans..

Tensions further rose when, after brokering the release of two hostages held by the FARC, Chávez called publicly on Colombia and Europe to grant Colombia's largest insurgent militia the status of a legitimate force and not a terrorist group.

Chávez's accusations last week of a Colombia-US plot against him came as some 3,000 Venezuelan troops participate in a series of military exercises called Operation Caribe 01. Venezuela has been building up its military in recent years, signing contracts with Russia to buy 53 Mi-24 armored helicopter gunships and Sukhoi 30 fighter planes.

"To the degree that those capabilities come into theater, they certainly are of great concern not just to Colombia... but to the region and in fact very much to the United States," Admiral Mullen told reporters in Bogotá this month.

But Thomas Shannon, US assistant secretary of State for the Western Hemisphere, who accompanied Ms. Rice on her Colombia visit, told Colombian radio that a conflict was unlikely. "We don't see at the moment the possibility of any conflict between the two countries. On the contrary, I think that the two countries have such profound and important ties that their governments will look for a way to manage and control these kinds of problems," he said.

Colombia and Venezuela are each others' second-largest trading partners with bilateral commerce reaching about $5.5 billion last year. Even through the recent friction, trade has continued normally.

The mutual need is what makes many border residents feel at ease amid the acrimony coming from the two capitals. "What happens in Caracas and Bogotá has nothing to do with us here," says Gustavo Gómez, a Venezuelan mechanic, who, like most people on the border, has extensive family ties with Colombia. "We are brothers; we could never fight."