If only the migrant crisis we’re facing today were as simple as our slogans.

Pursuing a “Secure the border!” or “No human being is illegal!” policy would be so simple.

Unfortunately, the hundreds of Central American children filling a warehouse detention center in Nogales, Arizona, are symptoms of a complex web of problems.

So are the Guatemalan, Honduran and Salvadoran families that federal agents are delivering regularly to the Tucson and Phoenix Greyhound stations.

Yes, they represent an “urgent humanitarian situation,” as President Obama said last week. But they also represent our failure to apply the few measures in our power to a dynamic that is bigger than us.

Most importantly, they represent our lack of foresight.

Border Patrol agents have seen a spike in crossings by Central Americans and by unaccompanied children that began in 2011 and has been accelerating. They’ve also seen a shift in migration patterns, away from Southern Arizona and toward the Rio Grande Valley of Texas.

Combine those two trends, and we could have been prepared for a surge in Central American children in South Texas. But we weren’t, and the detention and processing centers there have become overwhelmed, which has led the agencies to send the Central American families and children to Arizona.

Three years after these trends began, there nevertheless was inadequate detention space in Texas and there is still only one federal immigration detention center for families — in Pennsylvania.

We also could have foreseen the more recent surge of the last few months as an unintended consequence of a humane policy.

Because of overcrowding in Texas, we’ve been letting undocumented parents with children free into the interior of the United States on the promise that they show up in immigration court. Some of them may well do that, but of course many will not.

And, predictably, word has spread in Central America: If you make it across Mexico and show up in the United States with kids, you will get free entry. Smuggling networks, wanting the business, have marketed the “kids-get-in-free” concept.

“For anybody that knows the dynamics of illegal immigration, absolutely it was predictable,” said Mike Nicley, retired chief of the Border Patrol’s Tucson sector. Reports from across the border have quoted Central American migrants citing the rumor of a new U.S. asylum policy relating to children. An AP reporter in Reynosa, Tamaulipas on the Texas-Mexico border last week quoted a Honduran woman in a shelter there saying, “Almost all the families in Honduras are emigrating because they heard this talk.”

This isn’t to say that the fundamental causes of people’s desire to leave have changed. Lack of educational and economic opportunity remain key underlying drivers, along with a desire to reunite with family members, the U.S. Conference of Catholic Bishops said in a report from Central America last year.

But there was one overriding factor, the conference’s delegation found: “Generalized violence at the state and local level and a corresponding breakdown in the rule of law have threatened citizen security and created a culture of fear and hopelessness.”

This dynamic isn’t unique to North and Central America. On the Mediterranean coast of Europe, people are preparing for another tragic “boat season” as migrants from the Middle East and Africa flee similar problems in their home countries and take dangerous cross-sea journeys. Those who make it into Italy and Spain have put those countries in a familiar conundrum.

So, we’re confronting global dynamics that are beyond our control, but we can do a few things to address the situation we’re facing and that we’ve helped create.

One is to treat the Central Americans here humanely while keeping an eye on them. We messed up by not having adequate detention centers or shelters ready when this tide of crossers arrived, but the government is at least reacting with some breadth and force now, with the administration asking Congress for an additional $1.4 billion to deal with the flow.

Another is to discourage future crossings. We don’t control the economic and social factors driving people out of Central America, but we can send a message that there is not an open-door policy for children traveling alone or with an adult.

Expeditiously flying new migrants back to their homes in Guatemala, Honduras or El Salvador could change the word-of-mouth message and discourage people from embarking on the costly, risky trip north. It could also save some of the millions the administration is seeking.

While this may seem cold-hearted to some, it is also a humane thing to do: The train journey many Central Americans take north through Mexico is so dangerous it is known as “La Bestia” (The Beast) or “El Tren de la Muerte” (The Train of Death). That’s before they even attempt the crossings of the Rio Grande or the desert.

We can make up for our lack of foresight by pulling the few levers within our reach.

Contact columnist Tim Steller at tsteller@azstarnet.com or 807-7789.On Twitter: @senyorreporter

Contact columnist Tim Steller at tsteller@azstarnet.com or 807-7789. On Twitter: @senyorreporter