A Scottish court sitting in the Netherlands this week convicted a Libyan of murder for the bombing of Pan Am flight 103 in December 1988. This verdict is the culmination of a long process. The bombing occurred over Scotland killing all 259 people on board, including 189 U.S. citizens, and 11 on the ground. The investigation continued for three years until U.S. and British officials concluded that two Libyans, one a member of Libyan leader Muammar Qaddafi’s intelligence services, had organized the bombing.

Armed with evidence gathered during the investigation, the United States and Great Britain, in March 1993, got the United Nations to impose sanctions on Libya until Qaddafi turned over the accused. He did so, after negotiating over the location of the trial, in 1999. The trial began in May, 2000. Now, the verdict is in. Abdel Basset Ali al-Megrahi, the Libyan intelligence officer, was found guilty. His alleged accomplice, Lamen Khalifa Fhimah, who worked for the Libyan airline, was acquitted.

What was on trial in the Netherlands was not just the two Libyans, however. Since the late 1980s, the use of legal proceedings against those who commit terrorism has been one of principal ways in which the United States has tried to combat terrorism. Since 1993 more than a dozen terrorists, some associated with attacks that have killed and wounded hundreds, have been brought back to the United States for trial.

The results of the Pan Am 103 legal process will raise again the question of whether this method of combating terrorism is effective. The bombing of Pan Am 103 could not have occurred without Qaddafi’s authorization, yet he is still free. The security services that made the bombing possible are still operating and could organize other attacks. Similarly, Usama bin Laden, the financier and facilitator of some of the worst terrorism of the 1990s, remains safe in Afghanistan, able to support more attacks, even though some of those who carried out these attacks are among those we have arrested recently.

It is certainly the case that the use of legal proceedings against terrorists is not a decisive weapon. But it does have beneficial results. The painstaking and quite remarkable reconstruction of what happened to Pan Am 103 and who committed the crime, allowed the United States to build support for sanctions against Qaddafi. Over time, these sanctions had an effect on the Libyan economy and, it appears, on Qaddafi himself, who came to feel isolated. The economic and psychological costs of sanctions were a significant element in the long multifaceted campaign to persuade Qaddafi to curtail his support for terrorism. This campaign has worked. Qaddafi is not the problem he was in the 1980s.

Similarly, following the indictment of Usama bin Ladin in 1998 for his part in the bombings of two U.S. embassies in east Africa, pressure has mounted on the rulers of Afghanistan, who have given him shelter. Both the United States and the United Nations have placed sanctions on the country, for example, demanding that bin Ladin be turned over to the United States or a third country for trial. Again, such measures will not produce results over night or by themselves. But over time, with other measures, the case of Libya and Pan Am 103 suggests, they will.

This is one reason why we should not give up the strategy of using legal proceedings against terrorists. Another reason is that we have few, if any, alternatives. Some counsel the use of military force, for example. But this is one of the weakest tools we have in the fight against terrorism. We are more vulnerable to terrorist attack than the terrorist are to our military force. In any campaign of tit-for-tat violence, we are likely to come out the worse.

In fighting terrorism, as in all our national security concerns, we should fight in a way that plays to our strengths. In the case of terrorism, this means using criminal investigations and diplomatic and economic sanctions. It means continuing our now more than three decade-long struggle to shape international opinion, making terrorism illegitimate and isolating those who support it.

Such measures, employed to good effect in the Pan Am 103 case, will not produce a decisive victory over terrorism. Such a victory is not possible. But if we remain steadfast, accepting inconclusive results and setbacks but struggling on, in the long-term, slowly but surely, the ultimate verdict will go in our favor.

David Tucker is a Member of the Board of Advisors at the Ashbrook Center for Public Affairs at Ashland University and an Associate Professor at the United States Naval Postgraduate School.