Image copyright Reuters Image caption President Obama has been unable to untangle the US from overseas conflict

For a president who was going to end America's involvement in endless wars overseas, Barack Obama spends an awful lot of time defending his war strategies.

In just the last two weeks, he gave an Oval address on the strategy against so-called Islamic State (IS), he visited the Pentagon and the National Counter Terrorism Center.

He made no new announcements, but his public comments were meant to reassure a jittery public after the attacks in San Bernardino as well as Paris.

As he starts a two-week holiday in Hawaii, he looks ahead to his last year in office with US troops on the ground in not one but three active conflicts: Iraq, Syria and Afghanistan.

Admittedly, the current US military deployments of a few thousand in total are a far cry from the height of US deployments to Iraq and Afghanistan, the two wars he had promised to end, while Syria is the one he tried to avoid until he felt it was no longer tenable.

But there is currently no likely scenario under which any of these wars will conclude by the end of Obama's second term.

So how did the American president get here? A combination of unforeseen events, a reluctance to adjust course accordingly and a very narrow definition of what constitutes a national security threat for the US.

Iraq withdrawal

Obama initially withdrew from Iraq during his first term to deliver on his campaign pledge to end the war started by his predecessor. After all the blood and treasure spent in Iraq, a war-weary nation was mostly grateful.

The last US soldier left Iraq in December 2011. In 2012 the Obama campaign boasted that "President Obama responsibly ended the war in Iraq and will end the war in Afghanistan."

Image copyright Reuters Image caption Mosul has become an Islamic State stronghold since the US pulled troops out of Iraq

The president was criticised for withdrawing too quickly, failing to pressure the Iraqis enough into an agreement that would allow a residual US force in the country to solidify gains and continue to help the Iraqis to build up their armed forces.

Administration officials insist that a small residual force in Iraq would not have stopped the advance of IS in 2014.

But a European diplomat focused on the region said: "If America had been in Iraq and had the right permissions, they would have forced aggressive action against ISIL (an alternative name for IS) from the moment the group had taken its first town."

It is possible to then imagine a scenario in which IS would not have been able to extend and consolidate its territorial control from Raqqa in Syria across the border with Iraq and all the way to Mosul.

There are now 3,100 US troops in Iraq training and helping the Iraqis fight IS.

Afghanistan reversal

In October, Obama also had to reverse his pledge to get all combat troops out of Afghanistan by the end of 2016 leaving 5,500 troops in the country instead, because of advances made by the Taliban and fears of a repeat of the Iraq scenario.

"Obama Adds Endless Afghan War to Legacy" and "Obama loses peacemaker legacy" were two of the headlines following the announcement.

Image copyright AP Image caption US troops will be retained in Afghanistan into 2017

The mistake, say Obama's critics, was made in 2009 when he announced both a surge in troops and a withdrawal date. It took Pentagon officials by surprise and allowed the Taliban to bide their time.

But it chimes with the president's desire to define any military mission clearly in scope and time and not allow the military to set the agenda for an endless mission with endless resources.

Much has been written about Obama's failures on Syria, perceived or real.

There are two clearly defined camps: those who insist that the US could have done more to shape events and to limit the chaos in which extremism has thrived, and those who believe nothing the US could have done would have made a difference in what was essentially "someone's else's civil war" according to Obama.

Even in the battle against IS, the president delayed action on the Syrian side of the border as long as possible.

Officials from countries in the US led coalition against IS have described a president dragging his feet to the effort, particularly at the start of air strikes against IS in Syria in September 2014. In October the US deployed 50 special forces in Syria.

In all three cases, the president's over-analytical approach may have, in fact, prolonged the conflict.

Media playback is unsupported on your device Media caption President Obama announces new deployment in Syria

But Jeremy Shapiro, a former State Department official during the Obama administration who is now at the Brookings Institution, said that the president was in tune with the mood of the country after the Iraq war.

The president often "delivered to the public the policy they claim they wanted, but people have inconsistent beliefs.

"They want the US do less on every single policy issue but they want to feel safer… They want to be less involved but more in control," said Shapiro.

Demand for instant solutions

Derek Chollet, another former State Department and Pentagon official during the Obama administration, said the problem stems from the gap between president Obama's long term strategising and the desire most people have for instant solutions.

"Obama is like Warren Buffett and the foreign policy community is like day traders," he said.

Chollet is writing a book about the president's foreign policy entitled The Long Game. It examines the need to focus on long-term strategic interests such as the relationship with China and climate change while tending to unfolding crises in the Middle East without letting them take over, dragging the US into unwanted places and sucking up much-needed resources.

Supporters of the president's approach believe history will eventually prove Obama right, dismissing concerns from high profile critics such as French president Francois Hollande.

In January 2015, after the attack against the Charlie Hebdo newspaper in Paris, the French leader made a direct link between the rise of IS and Western inaction in Syria.

Without naming the American president, Hollande referred to the decision not to strike Syrian government targets in August 2013, after a Syrian government chemical gas attack that killed 1,400 people east of Damascus.

Image copyright AP Image caption Francois Hollande linked the Charlie Hebdo attack with Western inaction in Syria

The attack had crossed president Obama's famous red line and the build-up to war was only averted when President Assad agreed to give up his chemical stockpile. The French were livid with President Obama's last minute U-turn.

"The fact we didn't go to war is seen as some big strategic failure," said Chollet.

"But if we had used force in 2013 we would be on the ground today (in Syria) in a big way…If we still had chemical weapons in Syria today we would be in complete hysteria."

But Chollet admits that there is a danger in underestimating the impact of current events on the long-term strategy.

No existential threat

The president's assessment remains that Syria and IS do not present an existential threat to the US.

His European allies argue it does because it poses a multitude of threats to them, from the rise of IS to the flow of radical jihadist fighters to and from Syria and the humanitarian tragedy of the Syrian refugees.

Image copyright US Army Image caption Obama has sent special forces to fight in Syria

In the Washington Post last month, journalist Fred Hiatt wrote one of the most damning assessments of President Obama's approach to Syria under the deceptive headline "Obama's Syria achievement."

Hiatt argued that the most surprising of President Obama's foreign-policy legacies was "not just that he presided over a humanitarian and cultural disaster of epochal proportions, but that he soothed the American people into feeling no responsibility for the tragedy."

President Obama may actually agree that it is in fact an achievement to have dulled American instincts that have encouraged presidents to go to war in the past.

But as his approval slips because of worries about his handling of the aftermath of the Paris and San Bernardino attacks, he is left with the conundrum of persuading the American people his understated approach to a world in chaos is keeping them safe.