As the public panic associated with the rapid spread of the H1N1 (Swine Flu) virus grows with each new reported case, there is increasing pressure to close our nation's international borders; a move that is not only economically damaging and fraught with operational peril, but also only marginally effective.

While the initial swine flu outbreak appears to have originated in Mexico, it has already spread to the United States and other countries. Cases have been reported in the media in at least eleven states as well as ten nations. Because of the presumed rapid spread from Mexico, some argue the United States must immediately close its southern border to stem the future tide of potential carriers. Fortunately, the Obama administration has decided that such a move is not appropriate at this time.

The numbers associated with a decision to close our borders are staggering. Over 400 million people entered the United States last year, with the largest number crossing from Mexico. The value of cross-border trade with Mexico alone was $365 billion in 2008; the value for Canada was even larger. Closing an economically productive border would have grave consequences for already troubled industries on both sides. Because we are the largest trading partner of both Mexico and Canada, a border closure initiated by the United States could be an economic Armageddon for our neighbors and friends.

Additionally, the costs to physically close our border, while difficult to estimate precisely, are universally considered onerous. If the legal ports of entry were closed, we would simultaneously need to ramp-up law enforcement support between official ports of entry to prevent illegal crossings. This would likely involve deploying thousands and thousands of National Guard or active duty troops - personnel that are crucial to support local pandemic response efforts in their home states - along the many remote miles of our borders.

A border closure of this magnitude would not happen overnight; a truly effective effort would take time. By comparison, Operation Jump Start - President Bush's 2006 deployment of only 6000 troops to the Southwest Border in support of the U.S. Border Patrol - took months of planning to initiate. While we could likely move faster in this crisis, we know that by the time troops are fully deployed and the border sealed to all traffic, it would, as others have said, "be like closing the barn door after the pig has left".

We also know that border closures are, unfortunately, as contagious as the flu itself. Initial closures can beget retaliatory closures on the world stage. Considering the current economic environment, the last thing that a struggling global economy needs is panicked, widespread disruption of worldwide trade with little practical epidemiological gain.

The reality is that closing our borders will not stop the spread of swine flu. Computer studies show that the impact of travel bans and closed borders are minimal in stopping the spread of a pandemic flu. Instead we should focus on the implementation of responsible prophylactic measures.

The government is already taking rational and appropriate steps to do so: informing and educating travelers on the risks of H1N1 and advising of precautionary actions; implementing active screening of travelers; distributing protective drugs to Customs and Border Protection officers at the border; activating quarantine facilities at the nineteen busiest international airports; closely monitoring the virus' spread; and working toward developing a vaccine. Given the prudent response efforts already underway, Secretary Napolitano is correct to say that closing the borders "would be a very, very heavy cost for what epidemiologists tell us would be marginal" effectiveness in containing the virus.

A decision to close our borders - to cut us off from the rest of the world - can only be supported by arguments based in fear and symbolism. While closing the border sounds like a simple solution to a perceived foreign problem, the reality is that the swine flu virus is now as much our problem as it is Mexico's. It is here, on our soil. Wasting economic resources and the time of responding officials, and further harming our economy needlessly by closing the border will not help meet this challenge.

As we move forward in this crisis, it is imperative that government homeland security and medical officials continue to make decisions based on facts and science. It is essential that we continue implementing the mitigation and response protocols set up to deal specifically with this crisis while remaining open to the world for business.