Donald Trump's new security adviser must learn to master chaos
After just four weeks, the Trump administration finds itself beset by problems, many of them related to national security: the botched executive order on immigration; a gush of leaks from the intelligence community and the messy departure of national security advisor Lieutenant-General Mike Flynn; and concerns, increasingly shared by Republicans in Congress, about reported links between Trump's circle and Russia.
Meanwhile, many senior positions throughout the administration remain unfilled, the President's economic message is being drowned out by his vituperative relationship with much of the mainstream media, and a pressing legislative agenda - including tax reform, overhauling President Obama's healthcare initiative, and a major new infrastructure program - seems stalled.
It always takes time to appoint a new team and then to bed down new structures and processes that suit an incoming president's priorities, decision-making style and preferences.
But these are more than the normal teething pangs of a new administration.
Often new presidents find themselves tested by external events. President George H.W. Bush had to respond to the Tiananmen Square massacre in his first six months. As a former CIA director and ambassador to China, at least Bush snr had experience under his belt. Within a few months of being elected, his untested son George W. Bush had to deal with a diplomatic crisis with China, when one of its fighters crashed into a US reconnaissance plane, and then of course with the unprecedented strategic shock of 9/11 later in his first year.
By contrast, President Trump's present travails are mostly self-inflicted. But he needs to get a grip on the turmoil, and quickly.
Not only is his new administration losing precious momentum, but the threats confronting the United States and its allies will not wait. ISIL and other terror networks; North Korea's rapidly developing weapons programs (within several years likely to include a long-range missile capable of striking the US mainland with a nuclear weapon); cyber threats; Iran; disintegration in Syria; Chinese assertiveness in the South China Sea - the list only grows.
Trump's national security team will also have to sort out their approach to Russia, as well as reassure anxious allies in Europe, Asia and the Middle East (Vice-President Pence, Secretary of Defence Mattis and Secretary of State Tillerson have made a good fist of this during their early travels).
After he was reportedly rebuffed by two candidates - high-profile General David Petraeus and Vice-Admiral Robert Harward, a former US Navy SEAL - Trump has settled on another senior military officer, Lieutenant-General H.R. McMaster, to replace the controversial Flynn as national security advisor.
McMaster is well credentialled. His appointment was quickly welcomed by Senator John McCain, often a strident Trump critic on national security. A decorated tank commander during the first Gulf War, McMaster has had numerous combat tours in Iraq and Afghanistan, where he will have served with Australian forces.
As well as a formidable warrior, McMaster is an outspoken iconoclast and one of the US military's most respected strategists and intellectuals. He has a PhD in history, authored an influential book on the Vietnam War and was one of the architects of the counterinsurgency doctrine that underpinned President Bush's successful 2007 "surge" in Iraq.
At a recent international security forum I attended in Halifax, Nova Scotia, he was unconventional, provocative and big-picture.
McMaster will need every ounce of his vaunted intellect and judgment to succeed in his new role.
Incoming presidents with scant national security experience - such as Trump (and before him Obama) - often seek to compensate by appointing former military officers to senior positions. Trump has taken this practice to a new level, with three retired or serving (in McMaster's case) generals in cabinet or other senior roles.
Former air force general Brent Scowcroft, national security advisor to Gerald Ford and Ronald Reagan, set the gold standard. He was shrewd, tough and discreet; as a result, he was trusted and effective.
But high-level military experience is no guarantee of success. Obama's first national security advisor, General James Jones, struggled to make an impact. He was sidelined and left within two years.
McMaster's experience combating terrorists and insurgents in the Middle East will stand him in good stead - President Trump has made the defeat of ISIL his highest national security priority, and the Pentagon is reportedly developing options for an intensified military campaign in Iraq and Syria.
However, the role will also test McMaster's diplomatic and bureaucratic skills. The new national security advisor will have to navigate interagency politics; develop effective working relationships with fellow general Jim Mattis at the Pentagon, as well as Secretary of State Rex Tillerson; and find a way to end the damaging row currently raging via the media between the White House and leakers in the intelligence agencies.
He will also need to restore flagging morale and fill numerous vacancies on the National Security Council staff, and establish a functioning national security decision-making process.
Even more challenging, to do that McMaster will need to find a way to work with the President's influential political Svengali, Steve Bannon, and an unpredictable new president with a jumble of views and instincts on foreign policy rather than considered or consistent positions - oh, and who tweets.