Last month, President Obama announced that the 1,200 U.S. troops working security on the Mexican border will stay through the end of the year. More than 17,000 border patrol agents are on duty along the 2,000-mile border, so the military's contribution is relatively insignificant.

Still, Obama's nod toward beefed-up border security seems to be playing well. Even Arizona Gov. Jan Brewer, who has had more than a few run-ins with the administration on border and immigration issues, applauded the decision.

The rare moment of Obama-Brewer accord actually demonstrates the lousy state of the public debate over how to fix American's broken borders. Like drunken sailors comparing tattoos, politicians boast about how many dollars, troops or miles of wall they've thrown at the border.

But the only way to actually secure the border is to reduce the number of people who dream and scheme to enter the country illegally. Hence, the only metric that really matters is the progress Mexico makes in becoming a safer, more secure, free and prosperous place.

The time for treating border security as a political issue is long past. America can't afford to let our leaders play politics when conditions in Mexico have become so serious. Transnational cartels are now so powerful and dangerous that they pose a real threat to national security on both sides of the border.

How bad is it? When was asked his "vision" for Mexico, one Mexican military officer said it was to see the country be like it was 10 years ago. Back then, he explained, the cartels would flee when the army showed up. Now, they fight back.

Mexicans know they are fighting for their future. And it's a deadly serious fight. The cartels have a saying: "plato o plomo" -- silver or lead. That's their offer: Either take a bribe and step aside, or we will kill you and your family. Some in Mexico are rejecting the choice. They are fighting back.

America's army could do to more to help, but sending more troops to the border is probably not the best use of the military's time. San Antonio-based Army North (aka, ARNORTH) is the command responsible for providing Army support to help the Mexican military develop the capacity to take on the criminal cartels and partner with the U.S. in joint operations that take on "the worst of the worst."

The Mexican military has been increasingly eager to "engage" with its U.S. counterparts. Just a few years ago, ARNORTH would conduct only two "engagements" -- mostly social affairs -- annually with its Mexican counterparts.

Now it does over 40 each year, and they are operational activities: training the Mexican military how to find and disrupt terrorist networks and protect and respect the civilian population.

With a decade of experience fighting hostile networks in Afghanistan and Iraq, the U.S. Army has a lot of expertise to offer its Mexican counterparts. What ARNORTH needs is more support ... and top cover.

Under ARNORTH, Joint Task Force North handles requests for military support from the Border Patrol, Customs and Border Protection, and other federal agencies. It can only fill about 20 percent of the requests it receives. That makes no sense.

Meanwhile, the Army's effort to build capacity in the Mexican military needs to be matched and integrated with what the other U.S. federal agencies are doing. No one is integrating efforts on both sides of the border into a coherent cohesive, proactive whole.

Ultimately, the only way to make the border safer is to upgrade security, prosperity and civil society in Mexico. Gestures calculated to win political points at home won't cut it. What's required is real effort ... on both sides of the border.

James Jay Carafano is a senior research fellow for national security at the Heritage Foundation.