Since the end of the Cold War, neglect of Latin America has become something of a fine art in Washington, practiced by Republican and Democratic administrations alike. But even in that context, the disregard for Mexico over the past couple of years is kind of astonishing.

The government of Felipe Calderón -- a pro-American moderate who just barely defeated a leftist populist in the 2006 presidential election -- is locked in a battle with drug cartels that will determine whether the country remains a modernizing democracy or plunges toward failed-state status. For violence and for sheer terror, the war resembles that of Iraq or Afghanistan. More than 50,000 Mexican troops have been deployed to fight the cartels; some 25,000 people have been killed in less than four years. Beheadings have become common, along with massacres, assassinations, gun battles on the street -- and now, car bombs.

The United States has not entirely ignored this crisis. But its efforts to help Calderón's government have been late, paltry and mired in bureaucracy. The Obama administration proposed $10.7 billion for civilian stabilization programs in Afghanistan and Pakistan in its 2011 budget; it requested $300 million in aid to Mexico. Congress has appropriated $3.6 billion for fencing along the U.S.-Mexican border, to keep out illegal immigrants. For the Merida Initiative, the program developed to assist Mexico's counternarcotics campaign, it has approved $1.3 billion since 2008.

As of March, $121 million of that appropriation -- or about 9 percent -- had actually been spent. Much of the rest, according to the GAO, was bogged down in more than a dozen federal agencies. The Mexican government was so frustrated by the delays that it advanced its own money for a anti-money-laundering operation, the report said. The State Department responded by reprogramming the money it had promised but never delivered.

This record of malfeasance is bad enough. But in Mexico's war, the United States also plays the role of supplier to the enemy -- and it does that far more efficiently. At a discussion sponsored by the think tank Third Way in Washington last week, Mexican Ambassador Arturo Sarukhán pointed out that the vast majority of guns and money flowing to the cartels come from the United States, including from 7,000 federally licensed gun stores along the border in Texas and Arizona. Eighty percent of the 75,000 guns seized by the Calderón government over three years came from the United States.

Calderón has pleaded with Congress and two administrations to reinstate the federal ban on assault weapons and to stop the massive illegal sales to Mexicans. Next to no action has been taken, despite Obama's rhetorical support for tougher enforcement. Sarukhán diplomatically noted that southbound inspections of vehicles for guns and cash have finally begun; but so far there have been only a handful of seizures.

The ambassador maintained that despite the red tape and failures of cooperation, "the formal diplomatic, bilateral relationship between Mexico and the United States is as good as it has ever been in the recent past." But "public perceptions on both sides of the border," he added, are something else. They are "running counter to where the formal, bilateral relationship is headed."

"Mexican citizens on my side of the border . . . believe that we're paying a heavy toll for what is basically a U.S. responsibility," Sarukhán said. So will they vote for a presidential candidate who would continue to pay that cost when Calderón's term ends in 2012? The ambassador said he thought so. But he might have added: that may depend on whether the Obama administration and Congress do more to help turn the tide in cities like Ciudad Juarez.