The law of diminishing returns has set in on the relationship between the United States and Pakistan.
One can already discern incipient signs of American disenchantment with Pakistan in general and President General Pervez Musharraf in particular.
These signs became noticeable to the people of Pakistan and even to outside observers during President George W Bush's 24-hour visit to Islamabad.
The lack of warmth during his interactions with the Pakistani leaders in general and Musharraf in particular stood in sharp contrast with the geniality displayed by the American President during his interactions with everyone, big and small, he met in New Delhi and Hyderabad.
Bush's admiration -- which he expressed frequently -- for India, its democracy, its civil society and its people stood in similar contrast with his noticeably pro forma remarks in Islamabad.
His words of praise in India were spontaneous and came from his heart. His restrained words of praise in Pakistan were uttered out of politeness by a guest to a host.
The change in Bush's demeanour was very striking and took his Pakistani hosts by surprise. The bonhomie that he had displayed towards Musharraf at Camp David two years ago was no longer there.
The American president that Musharraf encountered in Islamabad was disturbingly different from the Bush he had met earlier in New York, Washington and Camp David.
Even before embarking on his tour of South Asia, Bush had many warm words of praise for Musharraf in the media interviews given and statements made by him at Washington. He even referred to Musharraf as his buddy.
What happened between his departure from Washington and his arrival in Islamabad, which led to this change in attitude?
Reliable sources in Pakistan and Afghanistan attribute this to the briefings on the ground situation in Afghanistan, which Bush received in Kabul on March 1 from Afghan President Hamid Karzai and his officers, as well as from American military officers.
Since the beginning of this year, Afghan Army and intelligence officers had been openly criticising Pakistan for helping the Taliban to stage a comeback in Afghanistan, for giving sanctuaries to Mullah Mohammad Omar and other Taliban leaders and cadres in Pakistani territory and for providing them with training and arms assistance.
The Afghans were also pointing out that the majority of the suicide bombers in Afghanistan since the middle of last year were Pakistani nationals.
Pakistan media, Opposition slam Bush visit
The Afghans also claimed that trained and jihad-hardened Al Qaeda members were being sent by Abu Musab al-Zarqawi from Iraq into Afghanistan through Pakistani territory to help the Taliban.
Afghan intelligence officials also said that whereas the jihadi terrorists observed total communication silence while they were in Afghan territory, they resumed communications with each other and with their headquarters once they retreated into Pakistan.
This, according to them, reflected their confidence that no action would be taken against them in Pakistan even if their communications were intercepted.
During a trip to Pakistan before Bush's visit, President Karzai had brought these reports to Musharraf's notice. The Afghan president had also handed over to Musharraf a summary of these reports prepared by Afghan intelligence officers and a list of Taliban sanctuaries in Pakistani territory.
After Karzai returned to Kabul, the Pakistan foreign office spokesman dismissed these reports as unreliable and out of date.
In interviews to the BBC and other Western television channels, Musharraf made sarcastic references to these reports as inaccurate and unreliable.
'Bush snatched bread from our mouth'
Musharraf also alleged that Karzai was trying to cover up the incompetence of Afghan intelligence agencies and security forces by blaming Pakistan.
Musharraf's references were reported to have angered Karzai and his officers, who gave Bush a detailed briefing on the Pakistani involvement with the Taliban and Al Qaeda remnants operating in Afghan territory from Pakistan.
President Karzai and Afghan Foreign Minister Abdulla Abdulla reportedly accused General Musharraf of insincerity and told President Bush that so long as the Pakistani involvement continued, the ground situation would not improve in Afghanistan.
The Afghan briefings were totally corroborated by American field officers in Afghanistan during their separate briefings for Bush.
It is said that Bush was taken by surprise and disturbed by the details of the Pakistani involvement. Before his departure from Kabul for New Delhi, he had told the media that President Karzai had mentioned to him about the activities of the Taliban and Al Qaeda from Pakistani territory and that he would be taking this up with Musharraf.
This set off some concern in Islamabad, which immediately initiated some corrective action.
Last year, the Pakistani Army had made all Taliban leaders and cadres based in the Pashtun majority areas of Balochistan shift to the Waziristan area of the Federally Administered Tribal Areas of Pakistan, where the remnants of Al Qaeda, the Islamic Movement of Uzbekistan, the Jundullah (Army of Allah) and other components of the International Islamic Front were already based.
Bush on N-deal: India, Pak are different
The Pakistani Army concluded an informal ceasefire with them. It agreed to suspend its operations against them in return for their assurance that they would confine their operations to the Afghan territory.
Following this agreement, many of the Pakistani troops deployed on counter-terrorism duties in Waziristan, including the helicopters given by the US, were moved to Balochistan to start a military offensive against the Balochistan Liberation Army, which has been fighting for the independence of Balochistan.
After coming to know of the statement made by Bush in Kabul, Musharraf ordered a resumption of the counter-terrorism operations in North Waziristan.
The operations were resumed and over 40 people -- mainly Chechens, Uzbeks and some locals -- were killed on February 28. The Taliban, Al Qaeda and the IIF retaliated against it. The Taliban captured the telephone exchanges in North Waziristan and cut off all communications with the rest of Pakistan.
It also attacked posts of the Pakistani Security Forces in the area. The fighting is still going on with over 100 casualties suffered by both sides.
In view of the continuing activities of the BLA in Balochistan, the Pakistan Army has not yet been able to move back to Waziristan all the troops it had shifted to Balochistan.
The Pakistani security forces are facing great difficulty in repulsing the attacks of the Taliban, the Al Qaeda and the IIF.
Column: Why Balochistan is burningÂ
Meanwhile, the Jundullah, which had suspended its operations in Karachi in return for the suspension of the Pakistani Army's operations in Waziristan, resumed them on March 2.
It carried out a suicide bomber attack on a car of the US consulate in Karachi in which three officers of the consulate, including the head of the physical security set-up of the consulate, were going to work. The explosion killed the head of security.
This shook up the American officers responsible for Bush's protection, who were then in New Delhi.
It is said that even Musharraf was shaken up and worried over Bush's security in Islamabad.
He reportedly told his officers that they should accept -- without making it a prestige issue -- whatever suggestions their American counterparts had for strengthening Bush's security.
In New Delhi, the American officials reviewed the situation and decided that Bush should go ahead with his visit.
At the same time, they ordered a number of additional security measures.
Bush's plane arrived and took off from Pakistan Air Force's Chaklala airport at night in total darkness -- with all its lights switched off.
Pakistan was told that it would not be necessary for Musharraf or Prime Minister Shaukat Aziz to come to the airport to receive or see off Bush since the American officials were afraid that their movement to the airport in their security convoys could alert the terrorists.
Bush stayed in the American ambassador's house instead of a local hotel, which had been reserved for him and his party.
The American President was taken by the US Air Force in one of its helicopters to the ambassador's house and back as well as to the place of his meeting with Musharraf and back.
The air cover over Islamabad was provided by planes and helicopters of the US Air Force based in Afghanistan with officers of the Pakistan Air Force sitting in them to assist the American crew.
The Pakistan Air Force was asked to ground all its planes and helicopters till the Bush visit was over.
American secret service officers took over all the responsibility for the close-proximity protection of Bush. Their Pakistani counterparts were not kept in the picture.
These developments and the additional security measures necessitated by the Karachi explosion reportedly made Bush and his advisers realise how fragile the situation is in Pakistan and how unsatisfactory Musharraf's much-vaunted counter-terrorism operations have been.
Complete Coverage: Bush's South Asia visit
Another development, which took place even as Bush was in South Asia, contributed to the onset of the disenchantment.
Since 9/11, Musharraf has repeatedly reiterated his determination to close down the jihadi madrasas in Pakistan, expel all foreign jihadis studying there and to modernise the curriculum in the madrasas not associated with the jihadi terrorist organisations.
He has not implemented any of these commitments under some excuse or the other despite receipt of liberal grants from the US and other Western countries for modernising the education system.
The US and the United Kingdom again took this up strongly with Musharraf after the London explosions of July last year.
The General reiterated his promise to close down all jihadi madrasas and expel the over 1,400 foreign students studying there -- the majority of them from Southern Thailand followed by jihadis from South Africa -- by December 31 last year.
This was not done.
The madrassas continued to flout his instructions without any action being taken against them.
Exclusive interview: 'The Taliban have returned'
Just before Bush's visit, the Pakistani interior ministry decided to keep in abeyance the orders expelling the foreign jihadis on the ground that at a time when violent demonstrations were taking place all over the country over the Danish cartoons, the expulsion of the foreign jihadis could further provoke fundamentalist elements.
The seriousness with which Bush viewed the situation -- and his stern rebuke to Musharraf -- became evident in the US President's remarks at the press conference in Islamabad jointly addressed by him and the general on Saturday.
Bush said part of his mission was to determine whether Musharraf 'is as committed as he has been in the past to bringing these terrorists to justice -- and he is.'
'He understands the stakes, he understands the responsibility and he understands the need to make sure our strategy is able to defeat the enemy,' Bush added.
Well-informed Pakistani sources say that for the first time Bush and his advisers have started nursing misgivings about Musharraf's sincerity and his willingness or ability to help the US against Al Qaeda and the Taliban.
Has Musharraf outlived his utility for the US as a frontline ally in the war against terrorism? That is the question which must be troubling the minds of Bush and his advisers now.