ANOTHER HIJACKING, this one in Pakistan, where there are plenty of disaffected locals ready to use terror for political ends. Just one of those awful things where sober-minded governments had no choice but to deal with the terrorists -- right? Wrong. There was a difference in this latest case. You could call it the Soviet difference.

For the hijackers, the problem came down to finding a place where they and the prisoners they hoped to spring could go free. That is always the problem in hijackings: If there were no haven, there would be no hijacking, period. Having seized a domestic flight, where did the Pakistani hijackers go? Next door to Soviet-occupied Afghanistan, where they sat for some days at an airport entirely controlled by Soviet troops, meanwhile murdering one hostage. There they took on board not only food and gasoline but grenades, explosives and automatic weapons. Can you imagine a terrorist gang parking at Soviet-run Kabul and acquiring these supplies and weapons without Soviet cooperation? From Kabul the gang flew toward Libya, another Soviet client state, but finally put down at Syria, yet another Soviet client state, where hostages and prisoners were exchanged.

Pakistani officials, including President Zia, now allege a "deep conspiracy" between the regime in Kabul and the hijackers, and they suggest that the Soviet Union was behind an effort to destabilize Pakistan. It is specifically asserted that the Pakistani government has evidence that the leader of the gang had met with "Carlos" -- also known as Carlos the Jackal, a notorious terrorist and a figure closely tied to the Soviet KGB. It is further reported, by a passenger, that the gang leader boasted that he had been trained by the PLO, a group whose terrorist wing no longer bothers to conceal its relationship with Moscow.

Yes, it is a tangled skein, and yes, it would be hard to make the case stand up in an American court of law. But that hardly suggests that the Soviet Union should therefore be excused from any responsibility for this criminal episode.