With tens of thousands of unaccompanied Central American children entering the United States, last week President Obama announced his intention to use executive action to reform the U.S. immigration system. Immigration ­reform advocates all across the country breathed sighs of relief; opponents were outraged. The president's use of executive authority is far from ideal, even in the context of a dysfunctional Congress.

Historically, presidential efforts to enact even sorely needed legislation through executive authority or the exploitation of a partisan majority in Congress have proven unproductive, only hardening partisan divisions and political paralysis. That said, today’s immigration situation is unsustainable.

Here are the facts:

Upwards of 11 million undocumented immigrants currently live within U.S. borders. Over the past four years, some half­ million immigrants crossed the southern border illegally.

Recent headlines are still more unsettling: over the past seven months, 52,000 unaccompanied children have been apprehended crossing the border, mostly from  crime and violence torn countries of Central America.

This nearly doubles the same metrics for all of 2013—and another 90,000 are expected by year's end—figures which could double next year. Federal capacity to handle this influx is limited, and protests because of lax border enforcement in California and Texas illustrate the frustration of many.

What has become a political punching bag over the years has developed into a serious humanitarian crisis. And though illegal immigration is the problem we see today, the recent influx reflects the fallout from our own regional foreign policy.

Most of the immigrants that enter the United States originate in Mexico and Central America. U.S. policy toward these countries focuses on security cooperation, given the violence and instability resulting from the drug war endemic to the region.

But those same security problems, combined with lagging economies, are the primary drivers of immigrant flows, as Central Americans seek safety, security, and access to basic opportunities, all of which they are denied at home.

U.S.­-Mexico security cooperation is better than ever, delivering improvements in security, stability, and opportunity—including the capture of drug kingpin "El Chapo" Guzman this year. And the benefits of Mexico's growing economy is increasingly creating job opportunities, slowing the flow of Mexican migrants northward.

But as the problem shrinks in Mexico, it only grows in Central America—and the administration lacks an effective U.S. policy for dealing with the causes of migrant flows.

Failing to significantly increase the U.S. commitment to combating transnational crime and violence and providing economic opportunity throughout Central America only allows this problem to become more entrenched.

Though Vice President Biden recently requested an increase in Central America’s Security Initiative funding by US$160 million, this is too little, too late. As increased security in Colombia pushed transnational criminals to Mexico, joint security efforts in Mexico are driving the violence into Central America. As long as U.S. policy continues to be reactive rather than proactive, this pattern will repeat itself.

A more comprehensive policy is necessary to confront the challenges in Central America. Passing sensible comprehensive immigration reform would demonstrate that the United States is willing to begin work on these important issues —even when they stir up conflict here at home.

The growing humanitarian crisis will serve as a reminder to policymakers in the United States that our policy toward the region is far from deliberate, and that as long as we fail to deal with immigration reform at home, we will remain ill­ equipped to go beyond that and address the very roots of the problem farther south.

The longer we wait, the more difficult it will be for all involved. With the looming presidential season, Republicans and Democrats alike will find themselves under fire—the latter for failing to deliver on a promise central to their platform, and the former for their intransigence and alleged prejudice by a party faction against the fastest growing demographic group in the country.

Public opinion, moral imperative, and strategic interests all demand immigration reform. Congressional and presidential approval ratings alike are on the steep decline—and little is likely to be achieved before the midterm elections this fall.

But the administration has an opportunity to lay valuable groundwork now in the hopes that more meaningful, congressional reform might be achieved in the "lame duck period.” As expedient as executive action is, to achieve significant immigration reform Congress has to be involved. For sure it won't be easy; compromise never is. But the president's legacy might depend on it.

Meacham is director of the Americas Program at the Center for Strategic and International Studies.