Former President Trump on Tuesday said the United States' top military officer was guilty of treason if he went behind his back and promised to warn China of an impending attack. He was responding to bombshell revelations in a new book claiming that Gen. Mark Milley, chairman of the Joint Chiefs of Staff, twice called his Chinese counterpart last year over concerns that then President Trump was ready to go to war. 'If it is actually true – which is hard to believe that he would have called China, and done these things and was willing to advise them of an attack or in advance of an attack – that's treason,' said Trump during an interview with Sean Spicer on Newsmax TV. Excerpts from 'Peril,' by journalists Bob Woodward and Robert Costa, were published on Tuesday suggesting Milley feared Trump would launch a war in the wake of November's election defeat to Joe Biden . Milley sought to assure Gen. Li Zuocheng of the People's Liberation Army that the U.S. was not about to launch strikes in the calls. In one call he said he would use backchannels to alert his counterpart if an attack were imminent. The deadlines triggered a wave of condemnation from Republicans who demanded Milley's resignation and accusations of treason. An angry Trump dismissed the claims and said Milley was trying to distract from his own role in Afghanistan. 'I think he's trying to just get out of his incompetent withdrawal out of Afghanistan, the worst, the dumbest thing that anybody's seen … probably the most embarrassing thing that's ever happened to our country,' he said. Former President Trump accused the chairman of the Joint Chiefs of Staff of treason as he responded to claims on Tuesday that Gen Mark Milley told his Chinese counterpart he would warn him of any impending US attack amid Chairman of the Joint Chiefs of Staff Army General Mark Milley phoned his Chinese counterpart to give reassurances two days after the Capitol riot and cautioned US military leaders amid fears Trump might attack to keep power, according to a new book US intelligence reportedly concluded the government of Chinese President Xi Jinping was concerned about a potential US attack after the Jan. 6 riot The book's revelations triggered a wave of concern that Milley had violated the chain of command, endangering national security and breaking norms of civilian control of the military 'Peril,' by Bob Woodward and Robert Costa is published by Simon & Schuster on Sept 21 Trump repeated his frequent condemnation of the Biden administration's handling of Afghanistan before returning the allegations in the new book, excerpts of which were published by CNN , the New York Times and the Washington Post . Trump said: 'Milley made it up. he made this story about me attacking China. Think of it, I'm going to attack China. What's the reason exactly, other than that they screw a certain trade? 'You don't attack them for that.' And he described Milley's alleged behavior as 'a disgrace.' 'He was going to inform them when that will take place so they could be prepared,' he said. 'That is a treasonous statement and I cannot tell you how many people called up about it.' Trump named Milley to the top military post in 2018. However their relationship soured and details of their clashes have seeped into public view with publication of several accounts of the final days of the Trump presidency. The latest account details how Milley took a series of extraordinary actions after the Jan. 6th Capitol riot because he was concerned an 'unstable' President Trump might undertake military action in a desperate bid to stay in office. Milley met with top military officials in the Pentagon two days after the MAGA riot and told them to keep him in the process for all military actions, including the use of nuclear weapons. 'If you get calls, no matter who they’re from, there’s a process here, there’s a procedure. No matter what you are told, you do the procedure. You do the process. And I'm part of that procedure,' he told reportedly told them. He feared Trump was suffering 'serious mental decline,' according to the book, which relies on Woodward's well-established methods of relying on 'deep background' information provided sources, some of them anonymously, as well as documents and interviews, to attempt to reconstruct events and conversations.. 'The strict procedures are explicitly designed to avoid inadvertent mistakes or accident or nefarious, unintentional, illegal, immoral, unethical launching of the world’s most dangerous weapons,' he continued. 'Got it?' Milley asked his team members. 'Yes, sir,' they replied, in an exchange Milley considered 'an oath.' Milley also told CIA Director Gina Haspel: 'Aggressively watch everything, 360.' Just as stunning were Milley's reported actions that same date to the head of China's powerful military, to reassure his counterpart that the US was not going to attack China and set off a clash with a major nuclear power. His message, despite his own doubts about Trump's mental state, was that 'everything's fine.' 'Things may look unsteady,' Milley told Gen. Li. 'But that's the nature of democracy, General Li. We are 100 percent steady. Everything's fine. But democracy can be sloppy sometimes.' The military did not want an incident to set off a war with the major nuclear power Milley was concerned Trump might take military action in a desperate move to retain power Former CIA Director Gina Haspel Milley called China's People's Liberation Army (PLA) General Li Zuocheng to provide reassurances Milley was concerned Trump might go rogue, having run out of legal options to stay in office. Trump had called the election 'rigged' and spoke at a rally before supporters ransacked the Capitol It was Milley's second call to his counterpart in the final months of the Trump administration. US intelligence concluded the Chinese believed Trump might launch a military strike in order create a basis to stay in power, after an election Trump claimed was fraudulent, despite a series of court and procedural defeats that had him running out of options. Milley had earlier called Li in October amid ongoing tensions over the South China Straight, and Trump's rhetoric targeting China. Milley feared Trump might seek to use such an attack to achieve a Reichstag fire type incident, where he would cite the dangerous new situation to cling to power. Milley afterward concluded Li was 'unusually rattled.' According to the book, Milley even promised his counterpart there would be no surprises. They had reportedly established relations through a backchannel. 'General Li, you and I have known each other for now five years. If we’re going to attack, I’m going to call you ahead of time. It’s not going to be a surprise,' Milley reportedly told him. The book quotes Milley expressing concerns Trump might launch a strike that could lead to war. Trump campaigned repeatedly ending Middle East wars he called a waste, and negotiated a departure date with the Taliban in Afghanistan before leaving office. 'I continually reminded him, depending on where and what you strike, you could find yourself at war,' the book quotes Milley as saying of Trump. A president can only initiate a nuclear strike through a complex procedure that involves multiple layers of officials, coordinated through the National Military Command Center. Milley reminded officers of the process involved in authorizing military strikes Milley also spoke to House Speaker Nancy Pelosi, who had publicly raised her own fears about Trump's access to nuclear weapons immediately after the riot, which came on a day Congress met to count the electoral votes to make Joe Biden president. 'This is bad, but who knows what he might do?' Pelosi said. 'He's crazy. You know he's crazy. He's been crazy for a long time. So don't say you don't know what his state of mind is.' The authors cite a transcript of the call. Milley responded, according to the book: ' Madam Speaker. I agree with you on everything.' Pelosi told him: 'What I'm saying to you is that if they couldn't even stop him from an assault on the Capitol, who even knows what else he may do? And is there anybody in charge at the White House who was doing anything but kissing his fat butt all over this?' 'You know he's crazy. He's been crazy for a long time,' she told him. Milley's efforts to give himself the opportunity to potentially head off a strike or a war appears to have been triggered by his call with Pelosi. According to the transcript, she asked him 'what precautions are available to prevent an unstable president from initiating military hostilities or from accessing the launch codes and ordering a nuclear strike?' Milley then vouched for 'a lot of checks in the system.' Haspel had raised her own concerns after Trump refused to accept the results of the November election. 'We are on the way to a right-wing coup. The whole thing is insanity. He is acting out like a six-year-old with a tantrum,' she told him. 'This is a highly dangerous situation. We are going to lash out for his ego?' she told Milley in a call. The maneuvering came at a time after Milley had first accompanied Trump during his infamous photo-op shortly before authorities cleared protesters from Lafayette Square during Black Lives Matter protests in the summer of 2020. He then apologized for having participated in the event in uniform.