Mexican security forces after an attack by a drug cartel

A deadly car bomb last week, the first of its kind, suggests that Mexico's drug cartels are growing increasingly bold and sophisticated.  As illegal drugs and people cross the US-Mexican border into the United States, weapons and possibly billions of dollars in cash flow south.  Speaking in Washington Tuesday, experts  said fixes will have to be multi-faceted and long-term. 

A TV station caught on tape what was a first in Mexico's fight against drugs - a car bomb targeting police  detonated in Ciudad Juarez, across the border from El Paso, Texas.

At least three were killed in what's being viewed as an escalation in Mexico's already raging drug war.

U.S. State Department spokesman P.J. Crowley:

"Unfortunately, these drug cartels, they have enormous amount of resources at their disposal," said  P.J. Crowley. "They can buy any kind of capability they want.  But we are determined, working with Mexico, to do everything in our power to reduce this violence."

In Washington Tuesday, experts gathered to discuss steps the United States and Mexico should take moving forward.

Matt Bennett is Vice President of Third Way, a self-described moderate think tank. It hosted the event.

"It is not just a Mexican problem," said Matt Bennett. "Guns and money are flowing from the United States south and fueling this problem and drugs are traveling north…"

"It's a mutual responsibility between the U.S. and Mexico," said Henry Cuellar. "We cannot let Mexico fail."

Congressman Henry Cuellar says tightening the border alone won't do the trick. 

The U.S. has to help Mexico develop its police force, justice system, and courts. It's hard to catch drug traffickers in Mexico, Cuellar says, and once they are caught …

"...to prosecute someone, at least when I was down there, was less than a 2 percent chance," he said.

That's compared to a prosecution rate in the high 90s in the U.S., he says. 

"Once again I want to warn everybody, especially in Mexico, if you want to come to America through Maricopa County, we are going to have enough fire power to react to any assaults on our deputy sheriffs," said Sheriff Arpaio.

That's Sheriff Joe Arpaio of Maricopa County in Arizona.  Last week, while conducting his 17th immigration sweep, he brought out his "big gun," a machine gun.  He said his deputies needed it for protection while patrolling desolate areas where drug and immigrant smugglers have been spotted.

But Mexico's Ambassador to Washington, Arturo Sarukhan, says guns bought in states like Arizona are fueling the drug trade. 

He is calling on the U.S. to help plug the flow.

"Mexico has very stringent gun laws," said Ambassador Sarukhan. "You can't walk into a store and buy a gun like you can in this country."

The United States has announced it will send 1200 National Guard troops to the border with Mexico.  They will help keep a look-out for illegal border crossers and smugglers and assist with criminal investigations.

Mexico's drug violence has killed nearly 25,000 people since 2006, when Mexico's president launched an anti-drug offensive.