Ageing Antonovs and Ilyushins, museum-piece Dakotas, repainted Hercules C130s and veteran Russian bombers with the perspex of the rear-gunner's turret painted over are landing on the bumpy, hastily repaired airfields from which - only eight years ago - Soviet Migs and Hind helicopters took off on their vain mission to destroy the CIA-backed Afghan mujahedin fighters. For the Great Game, once fought out across the mountainsides of Afghanistan, is now being played in the air.
You can see the Russian pilots talking together in the shade of the paint- flaked fuselage of their Antonovs, most of them wearing old military fatigues. The word in Jalalabad is that most of the Russian crews here were Soviet pilots during the war in Afghanistan, and that the same men who once tried to kill the Afghan guerrillas are now resupplying them with guns. It may well be true.
The Bagram base, off the Kabul-Mazar road, roars with air traffic all morning as Tupolevs touch down from southern Russia. Bulgarian Antonovs bring mortars and ammunition, and - according to the Western aid workers who travel through Bagram - missiles as well. Some of the Antonovs carry the faded colours of the new state of Tajikistan, but no one doubts that they are fulfilling arms contracts for Moscow.
And if Russia is giving its logistical support to the notional government of President Burhanuddin Rabbani and his equally notional Prime Minister, Gulbuddin Hekmatyar - one-time guerrilla comrade, one-time enemy and now supposedly comrade again - it is equally easy to deduce which regional powers are resupplying the rest of Afghanistan's armies.
The Taliban militia - raised in the Islamic schools of Pakistan and now holding most of southern and western Afghanistan - are receiving regular flights from Saudi Arabia: anonymous, white-painted C-130s whose letter- codes betray their Saudi origin, and whose cargoes of green and white wooden boxes are received by squads of commandos who load them onto military trucks. "When you know that the Saudis are supplying people with arms, you know the Americans have given their approval," a mujahedin commander in Nangarhar province remarked nonchalantly. "And you can guess why the Americans have taken a liking to the Taliban fundamentalists."
In theory, of course, this is impossible. In the simplistic, public world of Washington politics, Islamic "fundamentalism" equals "terrorism", and most parties in Afghanistan - save for General Abdul Rashid Dostam's Tajik- backed forces in the north - officially fall into that category. But the Taliban are useful because - as Wahhabi devotees of the harshest form of Sunni Muslim orthodoxy - they loathe the supposedly apostate Shias of America's old nemesis, Iran.
Indeed, only two weeks ago, Taliban commanders in Kandahar invited locally based diplomats to a macabre stage-show which demonstrated all too clearly against whom their energies are directed. In front of an angry acting Iranian consul in Kandahar and before the beaming Pakistani consul, the Taliban's city governor paraded 70 Afghan prisoners in the local theatre. All, he said, had been caught crossing the Iranian-Afghan border on sabotage missions for the Iranian government.
Four of the young prisoners made public confessions. One described how, as a refugee living in Tehran, he had been arrested by security men at his government-supplied office job, taken to a training camp in eastern Iran, given two weeks' instruction in weapons and then told to "go and fight your enemies in the Taliban". The Iranian consul was outraged. The Pakistani consul, professing his country's "total neutrality" in the Afghan conflict, went on to lavish praise on the Islamic forces of the Taliban. So, add Pakistan to the list of Taliban supporters alongside Saudi Arabia and the US - the very triumvirate which armed the Afghans to fight the Soviets in the early 1980s.
Nor are the Taliban unaware of the identities of those who support the authorities in Kabul. Last October Mig jets flown by Taliban pilots forced a Russian Ilyushin-76 cargo aircraft en route from Russia to Kabul to land in Kandahar. It was packed with weapons, and its seven-man Russian crew were taken prisoner. They are still being held, along with their aircraft, at Kandahar airport. The Taliban believe that India is also resupplying the new Rabbani-Hekmatyar government in Kabul, partly to embarrass Pakistan, partly - so they claim - under the terms of a tacit Russian- Indian agreement to balance Saudi-American influence in the south of the country.
Across Afghanistan is a proliferation of newly opened consulates manned by diplomats of the regional powers. Iran now has seven consulates in the country, while Pakistan and India maintain lavish missions in the capital and in Jalalabad. And as the consulates have gained in importance, so, miraculously, have the local warlords acquired their very own airlines. Mr Rabbani virtually owns the old national airline of Ariana, while Hadji Qadir, governor of Jalalabad, has announced the opening of "Khyber Airlines" to link the Nangarhar provincial capital to Pakistan.
And Gen Dostam, whose Junbesh-e-Milli Islami alliance has received American blessing - not least, one suspects, because it controls the only oil and gas fields in Afghanistan - owns "Balkh Airlines", a one-plane outfit. The original British crew of its single BAC-111 jet reportedly walked out in horror when they saw Mazar-e-Sharif for the first time. (The stewardesses had apparently arrived in Islamic Afghanistan wearing skirts.)
Gen Dostam is now being wooed by the Rabbani-Hekmatyar alliance - the three would constitute a strong joint opposition to the Taliban - although the general himself sniffs insurrection in his northern statelet; and not without reason. Two weeks ago, while he was in Tashkent and his putative "foreign minister" Malik Palwan, was being generously entertained by US officials in Washington, Malik's brother Rasoul - who was Gen Dostam's own deputy - was gunned down in Mazar-e-Sharif, along with 15 of his bodyguards. Was the massacre carried out by those who opposed the general's flirtation with the Americans? Or - a more conspiratorial and darker theory - was Palwan murdered because of an internal power struggle with the general?
As the negotiations drag on for a central government alliance, the unexplained killings are likely to increase. Mr Hekmatyar's own arrival in Kabul as Prime Minister was greeted last month by a Taliban rocket attack that officially left 64 civilians dead although, according to the few Westerners in the capital, the fatalities could have numbered several hundred, since many bodies were buried within an hour of the slaughter. In Jalalabad, Mr Qadir is being encouraged to give his full support to the Kabul government - the main highway linking Jalalabad to the capital through the Kabul Gorge is open again - while Haji Qalili, the Iranian-supported commander in Bamian province, is being asked to do the same. If these two men make common cause with Mr Rabbani and Mr Hekmatyar, then Gen Dostam may be brought on board. At which point, participants in the Great Game - who will have lost substantial influence - will have to destroy the country's new unity.
Nor will this be difficult. If Afghanistan's warlords - and never was the cliche more accurate - see some advantage in unity through strength, their personal wealth and power relies on more than political alliances. For those aircraft bringing weapons to Afghanistan are not always flying home empty. The Antonov-12s bringing Japanese television sets to Jalalabad from the Gulf emirate of Sharjah - destined to be smuggled across the Pakistani border to Peshawar - have to be paid for, the palms of their crews well greased. And since Nangarhar produces 80 per cent of Afghanistan's opium, it is not hard to see how the Jalalabad mafia make their money.
The province boasts its own heroin laboratories and, despite the valiant efforts of some local officials to force local farmers to destroy their fields, the export of drugs now reaches out to the arms dealers who work, indirectly, for the major powers. And where do the drugs go? To Pakistan, of course. And across the western borders of Afghanistan - courtesy of the Saudi-American-backed Taliban - to Iran, where Iranian border guards are fighting fierce gun battles in the mountains with the smugglers. And - so the Afghans in Kabul say - to Russia out of Bagram airbase and out of Mazar, courtesy of Gen Dostam.
Just what the Hercules transports take back to Saudi Arabia from Kandahar is unclear, but a number of other flights between the kingdom and Afghanistan are supposed to be secret. Mr Rabbani's Ariana airline, for example, sends an unpublicised flight from Dubai to Jalalabad in the early hours of every Sunday morning. When pressed, airline officials say it is a freight flight, although passengers are carried in the rear section of the aircraft. Even odder is the fact that this flight originates not in Dubai but in the Saudi port of Jeddah. No one, of course, is suggesting that the national airline would conduct any nefarious traffic, but the Jeddah-Jalalabad connection raises intriguing questions, not least because the Saudi Arabian monarchy's fiercest opponent - the Saudi dissident Osama Bin Laden - has now exiled himself in Nangarhar province.
Afghanistan, it seems, is suffering a variation on a theme. The capital may be in ruins, the fields sown with mines, the people decimated by civil war and their own growing drug addiction. But the air lanes are open, and the sky above Afghanistan vibrates to the power of those who still play the Great Game.