The Islamic State is still receiving significant financial support from Arab sympathisers outside Iraq and Syria, enabling it to expand its war effort, The Independent quoted a senior Kurdish official as saying.
"There is sympathy for Da'esh [the Arabic acronym for IS, also known as Isis] in many Arab countries and this has translated into money - and that is a disaster," Fuad Hussein, the chief of staff of the Kurdish President, Massoud Barzani said.
He said that until recently financial aid was being given more or less openly by Gulf states to the opposition in Syria -- but by now most of these rebel groups have been absorbed into IS and Jabhat al-Nusra, the al-Qaeda affiliate, so it is they "who now have the money and the weapons".
Hussein did not identify the states from which the funding for IS comes today, but implied that they were the same Gulf oil states that financed Sunni Arab rebels in Iraq and Syria in the past.
The US has being trying to stop such private donors in the Gulf oil states sending funds to the IS that help pay the salaries of fighters who may number well over 100,000.
Dr Mahmoud Othman, a veteran member of the Iraqi Kurdish leadership who recently retired from the Iraqi parliament, said there was a misunderstanding as to why Gulf countries paid off IS.
It is not only that donors are supporters of IS, but that the movement "gets money from the Arab countries because they are afraid of it", he says.
"Gulf countries give money to Da'esh so that it promises not to carry out operations on their territory."
Iraqi leaders in Baghdad privately express similar suspicions that IS - with a territory the size of Great Britain and a population of six million fighting a war on multiple fronts, from Aleppo to the Iranian border -- could not be financially self-sufficient, given the calls on its limited resources.
But the IS appears to have the human and financial resources to fight a long war, though both are under strain.
According to the report in The Independent, the IS was conscripting at least one young man from every family in Mosul, which has a population of 1.5 million. It has drafted a list of draconian punishments for those not willing to fight, starting with 80 lashes and ending with execution.
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