For the first time since the Soviet invasion of Afghanistan in December 1979, a Soviet armored personnel carrier, filled with Soviet troops, rolled into Pakistani territory on March 18. It was commanded by a Soviet captain and flew a white flag.
An incredulous Pakistani commander, at the border post of Tor Kham, listened mutely as the young Soviet commander said -- in fluent English -- ``We know you have three Afghan Army defectors. We want them back.''
For the next three days, Tor Kham was bombarded by 123 rounds of heavy artillery and fire from Soviet T-55 tanks. By noon on March 20, the Pakistanis had sent the three Afghans back.
A warning given last month to the Pakistani President, Gen. Muhammad Zia ul-Haq, by the new Soviet leader, Mikhail Gorbachev, had been translated into action on the Pakistani-Afghan border. The attack on Tor Kham was neither the first nor the last direct Soviet-Pakistani confrontation since General Zia's Moscow visit. During the 50-minute meeting, highly placed sources say, Moscow issued its sternest warning to Pakistan to date: Stop supporting the Afghan guerrilla fighters, the mujahideen .
According to the sources, the Soviet leader minced no words: Moscow would no longer countenance Pakistan's providing the guerrillas with sanctuaries from which they conduct their raids. Moscow would also not ignore the flow through Pakistan of weapons and supplies for the mujahideen provided primarily by the United States Central Intelligence Agency.
The warning and follow-up action have come at a particularly delicate time for the Pakistani military ruler. Zia is under increasing domestic pressure to negotiate an Afghanistan settlement directly with the Afghan government. He is also being pushed to disentangle Pakistan from a conflict which, in this capital city, is increasingly being referred to as ``an American war.''
Each day, as though a reminder, there is the shrill cry of Soviet MIG fighter jets along the 1,000-mile Pakistani-Afghan frontier. There have been 61 bombings and strafings of Pakistani territory so far this year -- as opposed to 81 in 1984. In March alone, there were also more than 60 artillery attacks by Soviet forces, which are now within five miles of the border.
``The war has become deadlier and dirtier,'' a Western official said. ``The snows are melting. The spring offensive will soon begin. And it's become clear to us, and I believe to the Pakistanis as well, that Mr. Gorbachev is weary of the stalemate, and is prepared to considerably heighten the stakes.''
The war has created numerous social, economic, and political problems for a vulnerable Pakistan. There is growing apprehension among Pakistanis over any escalation of the fighting in Afghanistan.
Perhaps ironically some of the pressure which Zia may have to face will come from his 237-member parliament, which has already shown signs that it will not be as tame as the general had anticipated when he permitted highly proscribed elections in February.
When parliament convenes in May, a group of 60-70 deputies, including seven ranking retired military men led by a retired chief of the Pakistani Air Force, Air Marshal Nur Khan, will urge direct talks with Kabul. According to the air marshal, ``The country has not been taken into the government's confidence about our very heavy involvement in the Afghanistan war.''
It is a posture echoed by all of Pakistan's political parties, across the political spectrum, from the Marxists on the left to the Islamic religious parties on the right.
Zia, who is walking a fine line between his new civilian parliament and his eight-year-old martial law regime, was reportedly badly shaken by his meeting with Gorbachev. He came away with the impression that the Soviet leaders -- who have already sent 115,000 troops to Afghanistan -- would be prepared to commit up to 500,000 men.
The Soviets also appear to have lost interest in reconvening the moribund, United Nations-sponsored indirect Geneva talks between Afghanistan and Pakistan. The talks were last held in August and are aimed at finding a solution to the protracted Afghanistan war.
Meanwhile, Soviet helicopter gunships, during a particularly cruel four days in March, bombed and strafed the villages of Loe Dakka, Lalpur, Kama Dakka, Hureko, Ghani Khel, and Pekha Khwar. All hug the Pakistan-Afghan border on the Afghanistan side, and all are used as transfer points in the CIA arms pipeline.
The increasingly heavy concentration of Soviet forces on the border, seemingly intent upon destroying any building that could be used for the transfer of arms, has led Western and Pakistani officials to conclude that the Kremlin leadership may be embarking on its most serious campaign so far to totally cut the flow of Western weapons to the mujahideen. The largest share of assistance comes from Washington -- with a reported $250 million slated for aid this year -- in what has become a costly and well publicized ``covert'' war for the US.
The feeling that Pakistan has become the scapegoat for what are viewed by some as questionable US geo-political concerns, is also reportedly causing Zia some difficulty within his own 450,000-man Army as well. It is this Army that has provided his primary support for eight years of martial-law rule.
``I don't know what they're doing in Islamabad,'' one field commander said, ``but we're being squeezed increasingly -- by a regional power [India] on our eastern border, and a superpower on the west. And, as much as we say we'll protect our western border, we won't and we can't. It would give the Soviets just the provocation that they wanted to come across the frontier. So, we sit in our trenches, and follow Washington's dictate: ``We'll bleed the Russians to the last Afghan.' ''
Such talk seems increasingly apocalyptic in Pakistan's volatile Northwest Frontier Province, where 30,000 troops of the country's paramilitary frontier corps form what, according to Western sources, is an increasingly thin line of Afghan-border defense.
Of Pakistan's 16 Army divisions, 11 continue facing India to the east. And, despite a large-scale infusion of American arms -- including 40 F-16 jet fighters, M-48A5 tanks, armored personnel carriers, 155 mm artillery guns, air-to-air missiles, and 15 radar units designed to pinpoint enemy mortar fire -- field commanders say that the equipment is better suited for warfare against India in the plains, than to the rugged reaches of the Afghan frontier.
Whether the pressures on Zia will be forceful enough to change Pakistani policy on Afghanistan remains unclear.
Zia is highly dependent on military and economic assistance from Washington -- $3.2 billion from 1981-86 -- and cannot afford to openly antagonize his strongest ally.
Yet Washington has, on occasion, found Zia to be a frustrating and troublesome man, whose moves have often been impossible to accurately predict.