The irony of John Bolton's tenure as US national security adviser, which ended Monday night with a tweet from US President Donald Trump, was that when news of his appointment came to light, most foreign policy experts in Washington were concerned about the devastation Bolton could commit outside the country. He was known for his extremist views on North Korea, Iran and other issues. Many were worried about the wars this angry and mysterious man might convince inexperienced President Trump.

In fact, Bolton's legacy is not wars and destruction abroad, but his poor work in Washington. In 17 months of his tenure, he destroyed the National Security Council system, the complex structure that has governed US foreign policy since the end of World War II. Bolton's best-known exploits will continue to be his dismantling of a structure that has kept US foreign policy from falling apart into chaos.

President Trump is not the first US president to believe he can manage a foreign policy himself. During World War II, President Franklin Delano Roosevelt led the war effort from the Oval Office with a handful of aides. Roosevelt, who called himself a "juggler", was "quite ready to mislead and tell lies if that would help him win the war." He would like to keep his options open to everyone, including military commanders, diplomats, Congress and even Vice President Harry Truman.

After his death, several members of Congress, military officers, and some Roosevelt advisers formed the National Security Council and the post of National Security Adviser, to get all of Washington's political class involved in difficult issues. The result was not perfect, but at least there was an organized and authoritative structure of US foreign policy from another administration.

After the 2016 elections, President Donald Trump toured the White House, and he was surprised at the size of the cases placed on his office and the system through which these cases were conveyed.However, Trump did not serve in the military and did not serve in the government. Things got more complicated when the first national security adviser, Michael Flynn, resigned with a scandal.

Although he refused to take senior positions in the Trump administration, Bolton, who replaced General HR McMaster in April 2018, could have done a good job under an inexperienced president. But Bolton decided to break the system that has been the heart of US foreign policy for more than seven decades. Armed with his convictions about how the government works and how it should be run, he has something in his mind that is close to Roosevelt's juggling. The president was not with the National Security Council, but only with the National Security Adviser.

Bolton shattered the government and in turn destroyed it. As a national security adviser, he has been pushing hard on North Korea, Iran, Venezuela and Afghanistan, but without the structure behind him, and Bolton has begun to appear increasingly lonely as he tries hard to sell President Trump positions that the president is hard to accept. President Trump eventually broke away from Bolton and began consulting others outside the administration, such as Tucker Carlson of Fox News. When Bolton collided with the president, his regime collapsed, as reports of chaos in the decision-making on peace in Afghanistan and related talks illustrate.

Bolton's only achievement was the dismantling of the foreign-policy-making structure that relieved the president of foreign policy management. Bolton persuaded President Trump that he did not need to make the National Security Council make decisions, so the president is confident that he does not need the National Security Council either. Whether President Trump has nominated an alternative to Bolton is not important. It is impossible now that no one can convince the president that he needs the system itself, let alone the system in administration for seven decades.

Presidential sorcery seems to be back, and one does not need to compare Trump to Roosevelt. Today, Washington relies more on the presidency, and the world relies more on Washington's decisions than in the 1930s and 1940s. At the moment of division at home and chaos abroad, the disintegration of the federal government is the most anticipated crisis as a result.

John Gans is director of communication and research at the University of Pennsylvania

Bolton's only achievement was the dismantling of the foreign-policy-making structure that relieved the US president of foreign policy management.