Rawalpindi: From his prison cell, a senior Pakistani officer accused of plotting with a shadowy Islamist organization to take over the military released his political manifesto: His call was for the army to sever its anti-terror alliance with the United States, which he contends is forcing Pakistan to fight its own people. "This may help us redeem some of our lost dignity and we badly need that," Brigadier Ali Khan writes in the six-page document obtained by The Associated Press. The US, he says, might retaliate by cutting military and economic aid, but "do they not always do this at will? ... Our fears that the heavens will fall must be laid to rest." The manifesto reveals the ideological underpinnings of the most senior Pakistani military officer detained for alleged ties to Islamist extremists. The accusations against Brigadier Khan go to the heart of a major Western fear about Pakistan: that its army could tilt toward Islamic extremism or that a cabal of hardline officers could seize the country's most powerful institution, possibly with the help of Al Qaeda or associated groups like the Pakistani Taliban. Pakistani leaders dismiss such worries as ungrounded. Time for India and Pakistan to withdraw their troops from Siachen? Details of the case, made public for the first time by The AP, point to efforts by some Islamist groups to recruit within Pakistan's military, though their success appears mixed. They also give a rare look into the discontent among some in the military over the rocky relationship with the United States, currently on hold after American airstrikes killed 24 Pakistani border troops in November. Brigadier Khan, who was arrested a year ago, faces charges of conspiring with four other officers and a British member of Hizb ut-Tahrir to recruit officers to the group including the commander of the army's 111 Brigade, which covers the capital and has been historically linked to army coups. One witness at his ongoing court-martial said Khan discussed sending an F-16 jet crashing into the army headquarters, though that allegation has been withdrawn, according to Brigadier Khan's lawyer Inam-ul-Rahiem. Pakistan's army declined to comment on the trial, which is supposed to be secret. Hizb ut-Tahrir, which is banned in Pakistan and several other Muslim countries, professes non-violence and is not connected to terrorist groups like the Pakistani Taliban or Al Qaeda. But the outfit makes no secret of its desire to penetrate the armies of Muslim countries, particularly Pakistan, and foment an "Islamic coup" to establish a global "caliphate." In interviews, Brigadier Khan's family and two of his army colleagues insisted he was innocent and has been targeted because of a falling out with senior officers and his political views - particularly his stance against the alliance with the US Brigadier Khan's lawyer has denied the charges and says no concrete evidence has been presented at the trial. But one of the colleagues said Brigadier Khan did meet with members of Hizb ut-Tahrir and tried to enlist other officers, though the colleague played down the importance of the contacts. "He was easy prey," said the colleague, who spoke on condition of anonymity because he was worried about prejudicing the case. "He walked into a trap. He was fed up with the government and (army chief General Ashfaq Parvez) Kayani." But he said Brigadier Khan walked away from the group when it was clear his fellow officers were not interested in joining. The colleague said that he himself had also been approached by Hizb ut-Tahrir, via a cousin, but had turned them down. "Our brother is honest and outspoken," said Brigadier Khan's younger brother Bashir Ahmed. "He may have spoken against higher authorities and they don't like people to speak that way. That's why they are holding him." At a meeting with other officers days after the May 2, 2011, raid by US commandos that killed Osama bin Laden, Brigadier Khan spoke out against the operation, which he and others on the forces considered a national humiliation. Brigadier Khan was arrested on May 5 and his manifesto presents himself as a "victim" of the Osama raid. His lawyer, Rahiem, sought to submit the tract to a government commission investigating the Osama incident, but it was rejected. Some of the passages were included in a letter he sent to General Kayani some time before his arrest, Mr Rahiem said. The manifesto doesn't call for an armed insurrection, support Islamic militancy or mention Hizb ut-Tahrir. Rather, it is a refutation of Pakistan army's alliance with Washington, along the lines of what is often espoused by right-wing, Islamist Pakistanis. It buttresses its arguments with conspiracy theories, including that the United States was behind the Sept. 11, 2001, attacks. In Afghanistan, he recommends a United Nations force of mostly Muslim nations to replace the current US-led one. Pakistan's army has has long portrayed itself as a bulwark against extremism, even as it has to sought to harness militants to fight for its interests in Afghanistan and India. While many officers are secular or irreligious, a growing number are thought to have embraced a more conservative form of Islam over the last 10 years, like the country they are drawn from. Brigadier Khan was known to be a conservative Muslim. At army staff college, he had the nickname "Mullah Rocketi" - roughly "rocket cleric" - and was lampooned in a graduation skit as a cleric, said one of his colleagues. At the same time, anti-Americanism has been rising, fueled by anger at US drone strikes in the tribal regions, the killing of two Pakistanis by a CIA contractor in 2011 and the US border post attack in November. Some soldiers and officers have carried out occasional, but serious, terrorist attacks against the institution they once served. Militant sieges against army headquarters in Rawalpindi in 2009 and against a navy base in Karachi weeks after the Osama raid are both alleged to have had inside help. The 600,000-member army releases little data on its enrollment or makeup, so its hard to say whether it is undergoing Islamization. A study last year on what limited data found no evidence the force was recruiting disproportionately from conservative areas of the country. Lieutenant General Khalid Rabbani, who commands 150,000 troops in the northwest leading the fight against militancy, scoffed at the notion his men could become attracted to extremism. "This is absolute rubbish, leaps and bounds away from reality," he said. "We are as disciplined a force as the British or American or any other first class army in the world." Pakistan, a nuclear-armed country teeming with disgruntled Muslims, is a strategic priority for Hizb ut-Tahir, ex-members and analysts said. A Britain-based spokesman for Hizb ut-Tahrir, which is strong among British Pakistanis, declined comment on Brigadier Khan. But he said the group has recruited officers and would continue to do so. "We call on the people in the armed forces to use their authority and fulfill their Islamic duty of stopping the political and military leaderships' transgressions," Taji Mustafa said in an email.