When we suggested at the beginning of this year that the United States should seize the moment to improve relations with the rest of the hemisphere, we made trade the No. 1 item on the policy agenda. Finally in 2011, after seemingly endless delays, Congress ran out of political excuses and approved the free-trade treaty with Colombia and Panama.

The successful effort to cement our economic bonds with the rest of the Western Hemisphere may be the most important achievement for U.S. policy in the region in 2011, a year dominated by headlines over criminal rampages in Mexico and elsewhere and the rants of anti-American leaders like Venezuela’s Hugo Chávez.

Mr. Chávez recently led an effort to form a large bloc of hemispheric nations with an anti-American agenda, but its lack of structure and financing calls its seriousness into question. Mr. Chávez and his cronies are merely playing the anti-yanqui card in an effort to consolidate their own power. Here’s a bulletin for them: The days when Latin America was a “backyard” for any of the major powers has long been over.

Meanwhile, the smarter leaders of the region — led by Brazil’s spectacular economic growth — are looking toward the future. In a signal of new-found confidence and vision, Peru, Chile, Mexico and other Pacific nations decided to form a trading bloc with Asia. President Obama, who said at the recent summit with Asian leaders that the United States is thinking along the same lines, should welcome this effort.

Around the region, several countries are likely to be the focus of events in 2012:

Venezuela. Mr. Chávez has converted his country into a virtual headquarters for Iranian espionage in the Western Hemisphere. The United States may not be able to break the Caracas/Tehran axis arbitrarily, but it must remain vigilant and expose Iranian activities whenever possible. Mr. Chávez’s infirmity from cancer has raised political jitters. If the Organization of American States wants to remain relevant and credible, it must be ready to blow the whistle on efforts to hijack the democratic process in next year’s elections.

Haiti: Nearly two years after the cataclysmic earthquake of January, 2010, the recovery remains painfully slow. The country has managed to avoid being hit by a hurricane, but it’s not ready for another major storm and its luck can’t last forever. Less politicking by President Michel Martelly and Haiti’s politicians would ensure that everyone is pulling in the same direction.

Cuba: The heavy hand of the state will guarantee that Raúl Castro’s pathetic efforts to breathe life into Cuba’s moribund economy go nowhere. The problem is the same as ever: It’s a police state that continues to beat protestors and deny freedom to its people. The country will remain trapped in a Marxist time warp. The Obama administration should continue to make the release of U.S. citizen Alan Gross an urgent priority.

Mexico: The horrible crime wave has endangered political liberalization by opening the door for the old-line PRI, a party that has opposed President Felipe Calderón’s all-out fight against drug traffickers. The United States must continue to help Mexico and hope the Mexican people understand the absurdity of making a truce with some of the worst gangsters on the planet.

Unfortunately, U.S. efforts to implement a more robust policy have been handcuffed by political gridlock in Washington. Republican senators, like Florida’s Marco Rubio, have opposed the nomination of the State Department’s Roberta Jacobson to head U.S. diplomacy in the Western Hemisphere. She is well-qualified and should be approved. Mr. Rubio also blocked Mari Carmen Aponte’s nomination as U.S. ambassador in El Salvador. She, too, was well qualified.

Senate conservatives say they want the administration to play a more active role in the region. Amen to that. But as long as petty politics and partisan division obstruct diplomacy, U.S. policies in the Western Hemisphere will be weakened at a time when U.S. leadership is most needed.