Considering that it is largely implausible and quite talky (even shouty), the CBS movie "Terrorist on Trial: The United States vs. Salim Ajami" is still a pretty good watch. The three-hour film airs tomorrow night at 8 on Channel 9 and gets the TV year off to a moderately ambitious start.

You could call the film preachy and probably be right. But at least it's a movie about something; it tackles a modern topic of global concern, and treats it with investigative intelligence. The topic of course is international terrorism. The trial, which happens "sometime in the future," is of a Mideast zealot who claims to have ordered the murder of five American tourists, some of them children, visiting Barcelona.

As the film opens, he is brought to Andrews Air Force Base where U.S. marshals take custody of him. Eventually he ends up in a very blue (literally) Alexandria, Va., courtroom where he is tried on some fanciful new statute meant to discourage attacks on American citizens abroad by authorizing the kidnaping of suspects to get them into a U.S. court.

The premise is obviously derived from real-life incidents, but somehow as "Terrorist on Trial" unfolds, this particular case seems highly unlikely. A great point is made of narrowing the case to a murder charge (despite the fact that the accused man was nowhere near Barcelona when the killings occurred), but once the trial begins it becomes a wide open debate on political morality.

A salient feature of this trenchant drama is, however, that you don't have to believe it to enjoy it or to be immersed in its arguments.

That's partly because the writers weave into their story some meaty considerations of real and wrenching issues. There are references to the Achille Lauro incident, the Rome airport bombing, the TWA hijacking and other infuriating or conscience-troubling events. The question is even asked if the dropping of the bomb on Hiroshima was perhaps an act of "terrorism." It wasn't, but it doesn't hurt to ask.

There's also a volatile subplot: The brilliant law professor asked to defend the accused Arab in court is Jewish. When he's considering taking the case, a pro-Israeli group visits him and urges him not to. He declares, "I'm a secular Jew; some of my best friends would be Arabs -- if I knew any."

He takes the case because he sees it as an instructive exercise in the glories of due process. And he tells his students, "The only plus about defending the indefensible is that nobody expects you to win."

Ron Leibman, who played the union organizer in "Norma Rae," seems much the same hero here in the role of the lawyer, Simon Resnik. Sam Waterston plays the prosecutor and Robert Davi is the unrepentant Salim Ajami, apparently cast in the part because he looks a little like Libya's Moammar Gadhafi.

But the real stars of the production are Richard Levinson and William Link, the writing and producing team that has made a specialty of the topical, thoughtful, controversial TV movie. They did "The Execution of Private Slovik," "That Certain Summer" and "Crisis at Central High," films that dealt with wartime morality, tolerance of homosexuals and racial bigotry.

On March 12, 1987, Richard Levinson died. "Terrorist on Trial," dedicated to him, is thus the last Levinson-Link collaboration. It's not the team's best work, but it is a proud note on which to conclude an exemplary television career.

In their lighter moments, Levinson and Link created such durable TV series as "Columbo" and "Murder, She Wrote." But they will be remembered for daring to be serious and relevant in prime time -- something fewer and fewer writers and producers seem prepared to be, and something the system persistently discourages.

The filmmakers try to keep the terrorist's nationality vague -- it's speculated that he's "either Lebanese or Syrian," or maybe neither, and stated that "to some in the Arab world," but not all, he is "a hero." An Arab antidiscrimination group has already lodged a protest against the film, charging that it fails to mention Israeli mistreatment of Palestinians for fear of alienating American Jews.

One of the subjects explored by "Terrorist on Trial" is the way terrorists attempt to use television. Of course nearly everybody attempts to use television sooner or later. Levinson and Link were among the few who tried to use it responsibly.

As the economic stakes of television rise, network timidity grows. Controversy appears to frighten the networks more than it used to. But a hot potato like "The Day After" or "Terrorist on Trial" is good for television and for viewers. One such film is worth 10 glossy movies about celebrity murders or the peccadilloes of the rich.