Obama warns IS 'madmen' would gladly use nuclear weapons

By Andrew Beatty and Thomas Watkins

Islamic State “madmen” wouldn’t hesitate to launch a catastrophic nuclear attack, US President Barack Obama warned global leaders at a meeting in Washington on Friday.

Hoping to galvanise global action to prevent IS from getting hold of nuclear weapons or material for a "dirty bomb", Obama painted an apocalyptic picture of the impact of a nuclear terror attack. 

That threat has loomed large over the two-day summit, amid revelations that the Islamic State (IS) group carried out video surveillance on a top Belgian nuclear scientist.

"ISIL has already used chemical weapons, including mustard gas, in Syria and Iraq," Obama said, using an acronym for IS. 

"There is no doubt that if these madmen ever got their hands on a nuclear bomb or nuclear material, they most certainly would use it to continue to kill as many innocent people as possible."

The summit - attended by dozens of world leaders and delegates - is focused on securing global stockpiles of nuclear materials, stored by the military and by the medical and power industries.

Obama said about 2,000 tonnes of nuclear materials are stored around the world at civilian and military facilities, but some of them are not properly secured.

"Just the smallest amount of plutonium - about the size of an apple - would kill and injure hundreds of thousands of innocent people," he said. 

"It would be a humanitarian, political, economic and environmental catastrophe with global ramifications for decades," he added.

“It would change our world."

The nuclear security summit comes in the wake of attacks in Paris and Brussels that have killed dozens and exposed Europe's inability to thwart destabilizing attacks or track Islamic State operatives returning from Iraq and Syria.

"As ISIL is squeezed in Syria and Iraq, we can anticipate it lashing out elsewhere," he said.

"We need to do even more to prevent the flow of foreign terrorist fighters." 

Shadows of Putin, Trump

This is the fourth in a series of nuclear security summits convened at Obama's behest and with the president leaving office next year, it may well be the last.

But it risked being overshadowed by two men who were not even there: Republican presidential frontrunner Donald Trump and Russian President Vladimir Putin.

Experts say Putin's refusal to attend has made it almost impossible to achieve substantive reductions in fissile material - the vast majority of which is held by the militaries of Russia and the United States.

"This nuclear security summit is supposed to address all of the stocks, but truth is that all they address really is a small proportion of civilian stocks," said Patricia Lewis, international security research director at British think tank Chatham House.

Obama foreign policy adviser Ben Rhodes earlier described the lack of Russian participation as "counterproductive".

America's presidential election also took center stage, with questions about Trump's suggestion that Asian allies should develop nuclear weapons.

"It would be catastrophic for the United States to shift its position and indicate that we somehow support the proliferation of nuclear weapons," Rhodes said. 

Erdogan and the Turkish media

In another development, Obama said he was "troubled" by the path President Recep Tayyip Erdogan is taking Turkey down, amid rows over press freedom and the war in Syria.

"It's no secret that there are some trends within Turkey that I have been troubled with," Obama said, when asked whether he considers the Turkish leader an authoritarian.

"I think the approach they have been taking toward the press is one that could lead Turkey down a path that would be very troubling."

Obama said he had expressed these sentiments to Erdogan "directly."

The pair met at the White House on Thursday for talks away from the cameras.

Ahead of the trip, the White House had suggested Obama would not formally meet him, prompting suggestions of a snub.

The possibility of no meeting had been glaring - the two countries are meant to be close NATO allies in the thick of a fight against the Islamic State group in Syria.

But tensions have been stirred by Ankara's attacks on Kurdish militants, some of whom are seen by Washington as the best bet for tackling IS fighters in Iraq and northern Syria.

Turkey says the groups are linked to the outlawed Kurdistan Workers' Party (PKK), which has fought a long battle for Kurdish independence and is seen by Ankara and Washington as a terrorist group.

Turkish forays into northern Iraq have also strained ties.

Before the meeting with Obama, there were ugly scenes when Erdogan gave a speech at the Brookings Institution, a Washington think-tank.

Ahead of his arrival, Turkish security officials clashed with protesters - both sides exchanging insults and scuffling - before police were able to separate them.

The US National Press Club accused Erdogan of trying to export oppression.