Pakistan is becoming a key piece on the geostrategic chessboard over which the United States and the Soviet Union confront each other in Southwest Asia and the Gulf.
This is the key to understanding the immediate fallout from the recent 14- day hijacking of a Pakistani airliner, eventually freed in Syria. The hijacking took place against the background of:
* The delicate and mostly behind- the-scenes maneuvers by the US to involve Pakistan and its considerable potential military strength in the overall Western security plan for Southwest Asia, including the Gulf.
* The parallel and related effort by Pakistan's military leader, General Zia ul-Haq, to defuse growing opposition at home and strengthen his position as deserving of US confidence and aid.
The unusually vigorous US intervention, critical of Soviet behavior while the hijacked plane was on the ground in Afghanistan, was probably intended in part to show General Zia that the US under President Reagan was willing to go further in Pakistan's direction than it was under President Carter.
An offer of US military and economic help by the Carter administration shortly after the Soviet invasion of Afghanistan was turned down by General Zia as "peanuts." (General Zia feels threatened by the Soviet presence on Pakistan's border. Pakistan has withheld recognition from the Soviet puppet government in Kabul.)
Among those nudging the Reagan administration in the direction of Pakistan is Saudi Arabia, whose royal family has already taken General Zia under its patronage. Saudi Arabia, with its vast oil reserves and long coastline on the Gulf, has of necessity a central role in US planning for the area.
But how, it may be asked, can General Zia hope to be seen at home and abroad as a strong leader when, in the end, he gave in to the hijackers of the Pakistani airliner and freed the political prisoners whose release they had demanded?
Certainly General Zia will have to live with that decision -- and the consequent possibility that there may be an attempted repetition of the hijacking. But compensating him for that is the harm which the hijacking may well do to the powerful posthumous legend of the late Zulfikar Ali Bhutto, the former Pakistani prime minister, whom (in effect) he had executed in 1979.
After his execution, Mr. Bhutto -- in the role of martyr -- became a more threatening political challenge to General Zia and his military government than he had been when alive. Mr. Bhutto's Pakistan People's Party (PPP) -- now led by his widow, Nusrat, and his daughter, Benazir -- was the hard core of the nine-party coalition which in early February publicly committed itself to the ousting of General Zia and the restoration of democracy in Pakistan. In recent months, incidentally, there had been signs that communist sympathizers were trying to get in under the PPP umbrella.
For two years, General Zia has been trying in vain to discredit the Bhutto legend and to deprive the PPP of its persistent political appeal. Now the aircraft hijacking gives him an opening to get at the Bhutto family.
This is because the three hijackers who seized the aircraft and forced it to fly first to Afghanistan claimed to be members of a guerrilla group called Al-Zulfikar, named in honor of the executed Zulfikar Ali Bhutto. The secretary-general of Al-Zulfikar is Murtaza Bhutto, son of the late prime minister, who has been living in exile since his father's demise. Initially, Al-Zulfikar had apparently limited appeal within Pakistan, but recently left-wing students have been reported to be moving in under its banner.
Al-Zulfikar has no open, direct links with the PPP, other than the Bhutto family connection. Despite family ties, there is no evidence that either Mrs. Bhutto or her daughter approves of the terrorism and hijacking with which the young Murtaza Bhutto is apparently involved. The Bhutto women, for all their often provocative initiatives, profess loyalty to the ballot box as the route to power.
That has not prevented General Zia from using the hijacking as reason to place both Bhutto women under arrest once again. And he will probably make no public distinction between them and Murtaza Bhutto in efforts to use the hijacking to discredit the entire family.
The case against Murtaza puts him in questionable company and in questionable places at questionable times. He was reported to have arrived in Kabul, the Afghan capital, shortly before the airliner hijacking.
After the freeing of the hostages, a senior Pakistani official asserted that Murtaza Bhutto had some time earlier met international terrorist Ilyich Ramirez Sanchez, known as "Carlos," or "the Jackal." "Carlos," who has never been apprehended, has long been a primary figure in the global terrorist network active in many lands over the past decade.