A State Department spokesman, responding to the incursion in Arizona, said the incident stemmed from a “momentary misunderstanding.”  This statement is difficult to accept when there have been more than 40 incursions on the U.S-Mexico border since October of last year and over 200 similar encounters since 1996.  Clearly, Mexican military incursions are far from a rare occurrence.

The Departments of State and Homeland Security, which have downplayed these encounters in the past, have an obligation to forcefully address this incident and the likelihood of future incursions.  We must convey to Mexico that we will not tolerate their soldiers crossing into the U.S. without our knowledge or consent.  More importantly, we must continue building fencing and other infrastructure in problematic areas of the border, including those prone to incursions.

In fact, the incursion in Arizona would not have occurred if the Department of Homeland Security adhered to the original border fence mandate included in the Secure Fence Act.  The law — until it was amended — required that double-layered fencing extending 392 miles East of Calexico, California, to Douglas, Arizona, be completed by May 30, 2008.  Instead, the Department of Homeland Security supported a revision in the law to allow for the construction of only 370 miles of fence along the entire U.S.-Mexico border – not the 700 miles that was originally required.

If the Mexican military personnel are having difficulty identifying the exact location of the border, then security fencing will certainly make it clear to them.  Fencing not only deters dangerous border traffic, but it also serves to delineate the border.  The presence of fencing and related infrastructure would effectively limit future incursions and reduce the risk these encounters pose to the safety of Border Patrol agents on duty.

Building this infrastructure is an important step toward creating a secure and enforceable border.  Indeed, the Department of Homeland Security’s current plan for 370 miles of fencing is a step in that direction.  The agency should be commended as it works to reach its goal.  However, there continues to be a significant need for reinforced fencing in other border areas.  Given the proven success of border fencing in areas like San Diego and Yuma, The Department of Homeland Security should immediately expand fence construction to include the full 700 miles permissible under federal law.

The incursion in Arizona is just one more reason, amongst many others, to implement additional fencing and infrastructure on the border.  With the right effort, we can build on the progress we have made so far and construct 700 miles of new fencing by the end of this year.