Can we? India recently announced that it is closing loopholes in its visa and admissions policies of American citizens in the wake of information that the terrorist David Headley was using a tourist visa to live long term in India. http://timesofindia.indiatimes.com/india/Headley-fallout-India-revises-tourist-visa-rules/articleshow/5340584.cms (h/t Dinah Lord http://dinahlord.typepad.com/dinah_lord/2009/12/india-changing-visa-rules-thanks-to-us-terror-suspect-headley-.html)
Aside from the fact that we allow aliens from terrorist sponoring states and religions (e.g. Islam) to use non-immigrant visas to come and go as they please, basically living in the U.S. on tourist or business visas, we allow the same for non-terrorists, overwhelmingly those from third world countries, like Mexico, and, of course, India. The B-1/B-2 non-immigrant visa for tourists and business, is routinely and consistantly abused by holders of those visas. The worst culprits are Mexicans, who use the B-1/B-2 visa and its near cousin, the Border Crossing Card, as a permit to come and go as they please while living in the U.S. Others, of course, do the same, and it is a quite common problem. Basically, those holding these tourist visas come to the U.S., stay six months, take a short trip outside the U.S. and return, staying another six months, ad infinitum. Common sense would tell us that that be prohibited, but the legacy INS and the current Customs and Border Protection, were never on the ball, hit and miss on the issue. India has found the solution, but to be implemented, the U.S. needs to adopt what India has that we don't. Departure control where departing passengers for foriegn destinations are inspected at departure. Not just fingerprinting of arriving aliens, but inspection and fingerprinting of departing aliens. CBP wants to outsource this job to contractors or the airlines to collect departure information, but it is a job that should be done by CBP officers, who have the authority to cancel visas at departure for overstaying of alloted admission dates and patterns of living in the U.S. on a non-immigrant visa.
It will require that airlines and airports create sterile federal inspection areas similar to what is now in place for arriving passengers from foreign countries, but that cost will be minimal for large airports like San Francisco, Los Angeles, and New York. They will just have to designate an international departure terminal for all airlines, rather than allowing airlines to depart from their own terminals. It will be more expensive for smaller airports like Denver, but it can easily and quickly be done.
And obviously, we need to restrict the use of the B-1/B-2 and Border Crossing Card to legitimate visitors and visits. Any long stay should then result in a prohibition or restriction for follow on visits. Just remember, no one gets 6 month vacations unless you are retired. Any normal visitor should be restricted to one month maximum in the U.S. and no more than one visit a year, unless a business visitor, who logically only come for a few days at a time. Add this to departure control and you have another effective tool in the fight against illegal immigration.