President Barack Obama's timetable for U.S. forces in Afghanistan rattled nerves in that country and Pakistan on Wednesday, prompting diplomats to scramble to reassure the two countries at the center of the president's war strategy that the United States would not cut and run. In Afghanistan, Foreign Minister Rangin Dadfar Spanta, the only minister who commented on the speech, said the announcement that American troops could begin leaving in 18 months served as a kind of shock therapy, but caused anxiety. 'Can we do it?' he asked. 'That is the main question. This is not done in a moment. It is a process.' In Pakistan, Obama's declaration fed longstanding fears that America would abruptly withdraw, leaving Pakistan to fend for itself. Many in Islamabad, Pakistan's capital, argued that the short timetable diminished any incentive for Pakistan to cut ties to Taliban militants who were its allies in the past, and whom Pakistan might want to use to shape a friendly government in Afghanistan after the U.S. withdrawal. 'The most serious issue, as far as we see it, is the exit date,' said a senior Pakistani security official who spoke anonymously because he was not allowed to speak publicly. 'It will have serious implications.' Though U.S. officials went out of their way to brief senior leaders of both countries before Obama's speech, many of the people whose support will be crucial to carrying out the strategy -- lower-ranking politicians and military or intelligence officials -- did not receive briefings. The Pakistani public, which has long been suspicious of American motivations, reacted with hostility and suspicion. Leaders in both countries, at least publicly, offered near silence or only a tepid embrace of the Obama plan on Wednesday. President Asif Ali Zardari of Pakistan, who has been lashed in the Pakistani media for being too close to the United States, did not comment on the speech. Neither did President Hamid Karzai of Afghanistan, who has been smarting ever since he was forced to accept that he did not win the presidential election outright. In Afghanistan, a statement from the presidential palace noted only that the government welcomed Obama's new strategy for the support it offered in development and training for Afghan institutions and in protecting the Afghan people. It also commended the plan for the recognition that terrorists were operating in the region beyond Afghanistan's borders in Pakistan. That acknowledgment was precisely what offended many in Pakistan, where the official reaction was limited to a short statement issued by the Foreign Office welcoming Obama's 'reaffirmation of partnership.' Politicians, analysts and media commentators, meanwhile, filled the void with skepticism, concern or outright rejection of the Obama plan, and particularly its timetable. 'Is it in Pakistan's interest to antagonize the Afghan Taliban now, if they will be in power two or three years down the road?' said Ahmed Rashid, author of 'Descent Into Chaos,' explaining the thinking in Pakistani political and military circles. 'Will the Americans actually deliver after the withdrawal, when the value of Pakistan decreases?' Pakistani analysts and security officials expressed skepticism that America would be able to achieve in 18 months what it had failed to do in eight years, and they said they considered the military buildup to be more resources poured into what was essentially a losing strategy. 'Pakistanis are not convinced that another military surge will address the issue,' said Maleeha Lodhi, a former Pakistani ambassador to the United States. 'This is bombs and bullets bereft of a political strategy.' Pakistan is a prickly ally, harboring deep suspicions of U.S. efforts in a region it believes the United States betrayed in the 1980s, when it stopped all aid after the Soviet Union's withdrawal from Afghanistan. Afghanistan then collapsed into civil war, with more than a million refugees pouring into Pakistan, and al-Qaida set up shop in Afghanistan once the Taliban seized control. Today, Pakistan's relationship with the United States remains fraught, with much of it taking place out of the public eye. The United States runs a program of covert airstrikes that it does not acknowledge publicly. It is one of the only tools available to Obama in Pakistan, but its use is costly as it inflames Pakistani public opinion. While Obama has sought to highlight America's contribution to Pakistan -- it is the third largest recipient of American aid after Israel and Egypt -- the support goes largely unnoticed inside the country, because Pakistan's leaders shrink from highlighting it, out of fear the government will become a target of the rabidly anti-American media. As if to illustrate the point, as cool as the government embrace of the Obama speech was, an opposition politician criticized the government for not publicly registering its displeasure with parts of the speech. Newspapers struck a skeptical tone. One daily, The News, acknowledged in an editorial that Obama was trying to change the substance of U.S.-Pakistani relations, but said that the trust deficit was so deep that 'it is unlikely that Islamabad will be more attentive to an apparently war-weary U.S. and NATO than it was to a fire-breathing Bush administration eight years ago.' The lack of trust permeates the relationship. Pakistani military officials say that the United States does not warn them when it moves troops on the Afghan side, leaving holes in areas that Pakistani militants know about, but Pakistan does not. 'At times, we come to know about it through militants' intercepts,' said a senior Pakistani intelligence official. 'This is embarrassing.' The official said the Taliban would use the exit date to 'bide time, continue with the pin-prick strategy and wait it out until the Americans leave.' The Obama administration has tried to offset Pakistani concerns with long-term security guarantees, trade benefits, upgraded military equipment and greater regional cooperation with India. But a Pakistani official said details had not been made public because the offer had yet to be accepted. The Pakistani military sees India as the biggest threat in the region and is frustrated that the United States does not seem to acknowledge that. The disconnect has been a major irritant in relations, particularly as Indian influence in Afghanistan grows. 'This is where Pakistan's trust of the U.S. could very dramatically increase,' Rashid said, 'if it became know the Americans were trying to get the Indians to become more flexible.' In Afghanistan, the worries were closer to home. American withdrawal could spell immediate disaster for the exceptionally weak central government of Karzai, and Sparta, the foreign minister, said he had submitted a proposal to secure long-term U.S. assistance that close allies like Egypt and Israel currently received. In Kabul, an increase in troops was generally seen as a gesture of welcome strength. Yet in the south, where the civilian cost has been highest and there is a deep weariness of the war, the mood has been generally against the increase, since many fear it would cost the lives of more civilians. A senior security official who has been tracking al-Qaida praised Obama's plan, saying a surge of forces could undercut the insurgency in six months, since many of the Taliban were ready to negotiate and could be persuaded to swap sides. 'They need the Americans,' he said, referring to the Afghan security forces. The two countries drew different conclusions from Obama's speech. Spanta praised Obama's direct reference to safe havens in Pakistan. 'It is a tremendous change and progress,' he said, adding that it was first time Afghans had heard such words from an American president. But the Pakistani intelligence official saw it differently, arguing that Pakistan had carried out two military campaigns this year, reclaiming large areas of territory from the Taliban. 'It is very disappointing,' he said. 'It was unfair to dump al-Qaida on Pakistan.' 