Here we go again. Three more young soldiers killed in Afghanistan. Three more families plunged into bottomless grief.

Captain Bryce Duffy was 26. "We loved Bryce to the ends of the world and not a day will go by when he is not thought of,'' his people said in a written statement. Corporal Ashley Birt was just 22. Lance-Corporal Luke Gavin, 27, left behind a wife and three children, Joshua, 7, Holly, 5, and Olivia, just seven months. "I can't explain how we feel except that our hearts are broken,'' Mrs Gavin wrote.

Julia Gillard and Tony Abbott offered their condolences, and I do not doubt their sincerity, but then out came the empty cliches, the hollow justifications: "Seeing the mission through ... staying the course ... getting the job done." Abbott called it "Freedom's fight." And then we all set off to enjoy the Melbourne Cup.

How many more young Diggers must lose their lives, how many more Australian homes must know aching sorrow, before we recognise that we have no place in this dirty, unwinnable Afghan war.

Osama bin Laden is dead and al-Qaeda is reeling. The Taliban exists chiefly because it is nurtured by neighbouring Pakistan, nominally a US ally but in fact a venal and cynical sponsor of terrorism on the Indian subcontinent.

Last year, the Americans pumped about $US4 billion in economic and military aid into Pakistan. They have got little but treachery in return. One of the guiding lights of Pakistan's nuclear weapons program, A. Q. Khan, who has admitted selling nuclear secrets to Iran, North Korea and Gaddafi's Libya, is still an honoured figure in Islamabad. Bin Laden himself was captured and killed in a compound where he had lived safely for five years about a kilometre from the Pakistan Military Academy.

In just the past few months, lethal terrorist attacks in central Kabul, including assaults upon the US embassy, NATO headquarters and the Intercontinental Hotel, were carried out by the Haqqani network, an insurgent group and Taliban ally with secure bases in Pakistan.

In September, the outgoing chairman of the US Joint Chiefs, Admiral Mike Mullen, laid it on the line. Haqqani, he said, was "a veritable arm" of Pakistan's military intelligence agency, the much-feared ISI. He bluntly accused Pakistan of "exporting violence" to the region. With friends like that ...

And there we are, stuck in the midst of this ghastly mess. Pakistan, a fellow Commonwealth nation, is backing the enemy that Australian troops are fighting. The Afghan government itself is corrupt and incompetent, presiding ineffectually over local warlords who are a law unto themselves.

There is no threat here to our national security; only to our troops. We should get out now.

Mike Carlton