Say what you like about past presidents and their international legacies, but it’s hard to dispute the caliber of their national security advisers.

From Henry Kissinger to Colin Powell, from Zbig Brzezinski to Sandy Berger, from Condi Rice to Susan Rice: the list is a long line in smart, seasoned and strategic thinkers.

Until now. Donald Trump’s decision to pick Lt Gen Michael Flynn as his most senior national security aide is a rupture with the past and with sane foreign policy.

Flynn is a conspiracy theorist and Islamophobe who hangs around the darker corners of the white nationalist internet. He also lost his last job in the intelligence services, I suspect because he can’t manage his way out of a paper bag.

All of which would be mildly amusing if Flynn wasn’t about to take on a job that will determine the immediate fate of large parts of the globe.

The president’s national security adviser plays a unique role inside the West Wing. Unlike almost every other corner of the presidency, national security is unquestionably controlled exclusively by the commander-in-chief.

Trump and Flynn make Bush and Cheney look like tenured professors of military history

Short of declaring war and obtaining a defense budget, the president needs nobody else’s say-so to unleash the world’s most powerful military, intelligence services and diplomatic corps.

Which is why the national security adviser is normally a stable, wise character who can sift through mountains of intelligence, maintain a clear sense of strategic priorities in the national interest, and wrangle the sprawling bureaucracy.

These are all qualities that are hardly obvious in Michael Flynn. Flynn has falsely claimed that Shariah law is spreading across the United States and that the nation is in the midst of a world war with radical Islamists. “Fear of Muslims is RATIONAL,” he tweeted earlier this year.

Flynn previously ran the Defense Intelligence Agency but lost his job after two years because of clashes with officials. For his part, Flynn claims he was fired because he opposed the Obama administration’s view that Islamist terrorists were a fading threat.

Like his new boss, Flynn appears very comfortable with the current Russian regime, working with Russia Today, the Kremlin’s propaganda TV network. He apparently received classified intelligence briefings while running a lobbying firm for foreign clients. He seems to favor working with Russia to combat Islamist terrorists while turning a blind eye to Russia’s designs on Ukraine and its support for the Assad regime in Syria.

As Trump’s trusted adviser, sitting in on his daily intelligence briefings, Flynn’s early record on advising the president-elect is shockingly undiplomatic: haphazard at best and unethical at worst.

In the brief time since he won the election, Trump’s first call with a world leader was not with a trusted US ally but with the Egyptian dictator President al-Sisi. He sat with prime minister Abe of Japan this week, but his aides told the Japanese not to believe every word Trump said.

He met with the populist right wing British politician Nigel Farage before meeting the British prime minister Theresa May. But he somehow found time to meet with several Indian real estate developers to discuss his property interests with them, and the Trump Organization signed a Kolkata deal on Friday.

Amid his many interactions with foreign powers, Trump is speaking without briefing papers from the State Department because his transition team is in such chaos that they have yet to establish meaningful contact with the nation’s foreign policy professionals.

Heck of a job, Flynnie.

We are condemned to repeat history if we choose to forget it. And Donald Trump’s voters have chosen to forget the lessons of the last Republican president.

After eight years of recovery from the catastrophe of George W Bush’s national security decisions, we are now staring at the prospect of an even more impetuous set of decision-makers. Trump and Flynn make Bush and Cheney look like tenured professors of military history.

Never mind that Trump spent most of the presidential campaign pretending he opposed Bush’s war in Iraq, when in fact he supported it. So far as anyone can fathom his position, it was to pick the winning position after the outcome was clear.

When a leader is both boastful and indecisive, the leadership vacuum is filled by aides who feed into the posturing but compensate for the indecision. Flynn fills that Trump-shaped hole perfectly.

But we know where this leads. Cheney cherry-picked manipulated intelligence reports to build a case for the war in Iraq that was the single worst US national security decision in a generation. We are still living with its consequences today, with Isis and a global refugee crisis that is unthinkable without the Iraq war.

Condoleezza Rice, Bush’s national security adviser, was unable to control the hawks inside the cabinet, even as she leaned towards the doves. Flynn doesn’t need to control any hawks, because he is leading the pack.

The opportunity for Flynn to cherry pick intelligence is almost limitless. With his public hatred of Islam and his desire to wage a war of religion, the case for military action will be simple inside the Trump West Wing.

It may be time to concede that one of the biggest winners of this election is the twisted and murderous worldview distilled by Osama bin Laden. Unlike Bush and Obama, Trump and Flynn believe we are engaged in a war with Islam, just as al-Qaida and Isis believe they are engaged in a war with Christianity and Judaism.

The jihadists have infected their enemies with their own sickness. To be fair, this infection had been growing for many years before Trump started running for office. It broke out when Congress – Democrats and Republicans – voted against the closure of Guantánamo Bay. It is obvious in much of the world’s refusal to deal with the Syrian refugee crisis.

But now the sickness has given us Trump and Flynn to escalate a religious-fueled war that is unwinnable.

By picking Flynn as his most powerful national security aide, Trump has confirmed what was obvious all along. He will govern as he campaigned, no matter what his aides say to reassure the world’s anxious diplomats.