Research and development was encouraged for future developments as well to continue to make security a priority (Airport Security, 1989, p. 2). Also in response to the bombing of Flight 103, the Aviation Security Improvement Act of 1990 was passed. Senator Wendell H. Ford opened the proceedings with the statement: "The terrorist bombing of Pan Am Flight 103 in December 1988 tragically demonstrated that something more is needed to be done to protect Americans traveling by air" (Aviation Security Improvement Act of 1990, 1990, p. 1).

In later hearings on implementation, it was noted by Thomas C. Kelly, Vice President of Security for the Air Transport Association, that U.S. airports were much safer than foreign airports and that this fact should be noted when dealing with this legislation: "Our primary focus in the development of this legislation was to ensure that it would contain provisions imposing the same extraordinary procedures on foreign flag carriers that the FAA currently imposes only on U.S. carriers operating in international routes" (Implementation of the Aviation Security Improvement Act of 1990, 1991, p. 110). Kelly notes that U.S. carriers must either physically inspect or x-ray all checked bags, make supplemental inspections of all carry-on bags, provide guards for all aircraft on the ground, and inspect all maintenance and service personnel with access to aircraft. U.S. carriers also perform redundant interrogations of passengers fitting certain profiles, appoint and train ground security coordinators, and accept no baggage from off-site sources. Such requirements are expensive and detract from the ease and speed of processing the passenger, which leads to another reason for demanding that foreign carriers provide the same degree of security -- to see that there is a level playing field in economic terms.

Clearly, these measures did not prevent the terrorist actions of 9-11, and that fact brought about a rethinking of many of the earlier measures, a strengthening of security measures, and the institution of new measures, many of which had earlier been rejected as intrusive and overly time-consuming. For the most part, American counter-terrorist actions with reference to airlines have tended to be reactive, and proposals for increased safety were largely ignored until 9-11, as Lansford (2003) notes:

For instance, in 1996, Clinton appointed Vice President Al Gore to head a commission on airline security. The commission issued a number of recommendations, including increased profiling...

However, the commission's recommendations were not accepted, partially because of opposition from the Department of Transportation and the Federal Aviation Administration because of costs (Lansford, 2003, para. 27).
Many of these same provisions have now been adopted, and the country seems much more willing to adopt measures that might add cost or that might increase inconvenience. Often, these measures are also reactive, though, as when a shoe-bomber was caught on a plane and now there are shoe inspections before a flight.

Counter-terrorism should be easier to implement in this climate, not just for airlines but for other venues as well, but the public does become weary of constant remainders of the potential threat and may begin to resist some of these measures. So long as the events of 9-11 remain in the public consciousness, however, such resistance will be minimal. The events in New York last week show this clearly as a concern for a threat to the subway meant stringent security measures for passengers, which meant a slowdown in commuting and other problems. The public accepted this with general equanimity, however, based on a memory of the bombings in Madrid and London a few months before. What the public really wants is for the government to find a way to reach the terrorists on their home ground and prevent them from attacking in the first place, but short of this, stronger security measures at home are adopted and accepted. This was true when the threat was largely of random hijackings and has expanded as the threat has expanded.