The Afghan president is walking a knife edge in efforts to bring peace to his war-ravaged country, balancing the interests of his neighbours and the Western countries supporting him, analysts said.
Recent reported arrests in Pakistan of Taliban players, including second-in-command Mullah Abdul Ghani Baradar -- the only detention Pakistan has officially confirmed -- have frozen Hamid Karzai's peace plan, they said.
Pakistan's Inter Services Intelligence (ISI) is believed to have been involved, in cooperation with the United States, and many in Afghanistan deeply distrustful of the agency accuse it of aiming to destabilise any peace process.
"Pakistan wants to show that if it is not part of the peace talks and is not involved in Afghanistan's affairs, then it can damage any plan and can cause huge problems," said Kabul University lecturer Wadir Safi.
Pakistan has been alarmed by the growing influence in Afghanistan of its arch-rival India and concerned by Karzai's request to King Abdullah of Saudi Arabia to help mediate in peace talks with the Taliban, he said.
Pakistan was one of only three countries to recognise the Taliban's 1996-2001 regime, which was overthrown in a US-led invasion, and is regularly accused of using the insurgents as a foreign policy tool in Afghanistan.
Karzai's government has said little about the arrests, but a deputy presidential spokesman at the weekend confirmed for the first time that they had a "negative impact" on efforts to broker a peace deal with the Taliban.
Siamak Hirawi's comments were the first official confirmation from the Kabul government that it had been in contact with the Taliban with the intention of discussing an end to the insurgency, now in its ninth year.
The former UN envoy to Afghanistan, Kai Eide, has also confirmed that arrests in Pakistan stopped the secret channel of communications with Taliban figures.
Ahmad Sayeedi, a former Afghan diplomat to Pakistan, said Baradar had been in contact with Kabul for at least five months, and his arrest had sent a message that the ISI would not tolerate being left out of any process.
"By arresting him, the ISI hits several birds with one stone -- first, they put the Taliban on notice about unilateral contact with Kabul; second, they want to sabotage the negotiations by making it clear that anyone who gets involved in talks will be punished," he told AFP.
"And third, they want to gain the trust of the United States by showing their active cooperation in the war on terror as a major offensive is ongoing in Helmand, to ensure they continue to get US funds and facilities."
US Marines are currently leading the first major offensive in a reworked counter-insurgency effort, in Helmand province, aimed at dislodging the Taliban from control of a number of poppy-growing regions in southern Afghanistan.
Commanders have said operations are also under way in Kandahar province, which the Taliban regard as their heartland, with extra troops set to boost the foreign military presence to 150,000 within months.
While US officials support reintegration of low-level Taliban fighters, many believe the Taliban should be dealt a greater blow militarily in order to give the Afghan government a stronger hand in any eventual peace talks.
"This is putting much more pressure on the Taliban," US envoy Richard Holbrooke has said, referring to recent arrests and eliminations.
"And this is a good thing for the simplest of reasons. It is good for the military efforts that are under way in Afghanistan."
Pakistani officials have insisted the arrests were not aimed at wrecking the talks, but Islamabad has said it can and wants to play an important role in promoting reconciliation and is willing to assist Afghan-led peace efforts.
"All the players should realise that they will not get the Taliban on board if Pakistan is not allowed in the process of reintegration and reconciliation," said Moeed Yusuf, South Asia adviser at the United States Institute of Peace.
"As for the US, it has not been able to give a clear signal as to what their political negotiations strategy is for Afghanistan. There are mixed signals."
