President Obama said Syria had become “ground zero” for jihadists as air strikes continued yesterday, hitting three makeshift oil refineries in the country’s Raqqa province.
Despite the aerial bombardment, a number of senior figures including the Republican speaker of the House of Representatives, John Boehner, called for troops to be deployed.
Prime Minister David Cameron yesterday defended Britain’s role in the air strikes after RAF planes carried out their first sortie over Iraq since Parliament gave the green light for action.
Speaking in a TV interview broadcast yesterday, president Obama said his country’s intelligence services had underestimated the threat posed by IS, while overestimating the ability of the Iraqi army to fight militant groups.
Mr Obama said Islamic militants had regrouped when US Marines quashed al-Qaeda in Iraq with help from Iraq’s tribes.
“Over the past couple of years, during the chaos of the Syrian civil war, where essentially you have huge swathes of the country that are completely ungoverned, they were able to reconstitute themselves and take advantage of that chaos,” he said.
“And so this became ground zero for jihadists around the world.”
Last week, the president expanded US-led air strikes into Syria and he has been seeking to build a wider coalition effort to weaken IS.
The group is thought to have killed thousands, including US journalists James Foley and Stephen Sotloff, and Scottish aid worker David Haines.
Outlining the military goal against Islamic State, Mr Obama said: “We just have to push them back, and shrink their space, and go after their command and control, and their capacity, and their weapons, and their fuelling, and cut off their financing, and work to eliminate the flow of foreign fighters.”
But he said a political solution is necessary in both Iraq and Syria for peace in the long term.
His comments came as opponents, including Mr Boehner, said “boots on the ground” were needed to defeat IS, also known as Isil.
Mr Boehner said: “If the goal is to destroy Isil as the president says it is, I don’t believe the strategy he outlines will accomplish it.
“At the end of the day I think it’s going to take more than air strikes to drive them out – at some point somebody’s boots have to be on the ground, that’s the point.”
Asked whether American troops would be needed, he replied: “We have no choice. They intend to kill us. These are barbarians, if we don’t destroy them first we are going to pay the price.”
Defending Britain’s limited role in the military intervention, Mr Cameron accepted a bigger contribution would be required from local forces in Iraq and Syria if it was to succeed in destroying the jihadis.
He said he had “a lot of sympathy” for the need to intensify operations in Syria as well as Iraq but had been constrained by a lack of political appetite in the UK for committing military forces to that country.
MPs on Friday approved strikes in Iraq but expressed caution over Syria – with Labour leader Ed Miliband calling for efforts to secure United Nations Security Council approval.
Mr Cameron has said he will seek fresh Parliamentary assent in advance for any such extension unless there is an immediate humanitarian crisis or a “unique British interest”, such as a hostage situation.
Two RAF Tornado GR4 fighter bombers returned to their base at RAF Akrotiri in Cyprus on Saturday night at the end of a seven-hour mission with their weapons payload intact having failed to identify suitable targets, the Ministry of Defence said.
British former senior military commanders questioned the policy of isolated air attacks.
Lord Richards of Herstmonceux, a former head of the UK military who stepped down as chief of the defence staff last year, said IS would not be defeated by air attacks alone and that a conventional campaign involving ground troops would be needed to crush them.
And Richard Williams, a former commanding officer of the SAS who served in Bosnia, Iraq and Afghanistan, described the deployment of RAF bombers as a “military sugar rush” that “risks looking fearful and half-cocked”.
Lord Richards said: “Ultimately you need a land army to achieve the objectives we’ve set ourselves – all air will do is destroy elements of IS, it won’t achieve our strategic goal.
“The only way to defeat IS is to take back land they are occupying, which means a conventional military operation. The only way to do it effectively is to use western armies, but I understand the political resistance.”
The air assault continued yesterday, with makeshift oil refineries and a plastic factory among the targets reported to have been hit.
IS fighters have control over oil produced in eastern Syria and have set up small, makeshift refineries to distil the crude into fuel, one of their main sources of income.
‘This is not a weekend campaign’
Driving out Islamic State (IS) militants will not be a “weekend campaign”, Defence Secretary Michael Fallon has warned, after the first sorties by RAF jets over Iraq failed to locate any suitable targets to strike.
The Ministry of Defence confirmed that the third mission to be carried out by Tornado GR4 fighter bombers since they were given the green light to commence air strikes had ended with them returning to their Cyprus base with weapons payloads intact.
Mr Fallon warned that operations could continue for weeks or even months. “This is not a weekend campaign,” he said. “This is going to take a long time.”
But Mr Fallon said that ultimately IS had to be defeated in Syria and that the government would keep open the option of returning to Parliament to seek permission to extend air strikes into the country.
He said: “The Americans are there with their air strikes, the other Gulf nations have come in … we shall have to keep under review whether we should be there too.”