WASHINGTON • American air strikes have killed 25,000 Islamic State in Iraq and Syria (ISIS) fighters and incinerated millions of dollars plundered by the militants, according to Pentagon officials. Iraqi and Kurdish forces have taken back 40 per cent of the militant group's land in Iraq, the officials say, and forces backed by the West have seized a sizeable amount of territory in Syria that had been controlled by ISIS.
But the battlefield successes enjoyed by Western-backed forces in ISIS' heartland have done little to stop the expansion of the militants to Europe, North Africa and Afghanistan. The attacks this year in Brussels, Istanbul and other cities only reinforced the sense of a terrorist group on the march, and among American officials and military experts there is renewed caution in predicting progress in a fight that they say is likely to go on for years.
Instead of engaging a pseudo-state in the Middle East whose fighters have proved susceptible to American air power, the United States and its European allies must also engage in a more complex struggle against home-grown militants who need relatively few resources to sow bloodshed in the West.
Attacks in the West are cheap to finance - Mr Jonathan Schanzer, a former terrorism finance analyst at the Treasury Department who is now with the Foundation for Defence of Democracies in Washington, estimated that the cost of the materials used in the Brussels attack and the lab needed to make the explosives, for instance, was from US$10,000 to US$15,000 (S$14,000 to S$20,000).
While some officials have sought to portray the recent attacks in Europe and Turkey as evidence that ISIS is growing desperate as a result of its battlefield losses, far more officials and experts see the violence as another indication that ISIS is not a problem that will be quickly or easily overcome.
But administration officials say that the twin efforts to militarily shrink the group's dominion in Iraq and Syria and to cut into its finances have fed off each other. Since late October, a US air campaign called Operation Tidal Wave II has targeted oil fields, refineries and tanker trucks, and US officials believe they have cut ISIS' oil revenue by about a third. On the ground, ISIS has lost a series of cities and towns since it seized Ramadi, Iraq, almost a year ago, its last major battlefield victory.
Coalition air strikes have, in the meantime, hit at least 10 depots where ISIS stored hard currency. The military said tens of millions of dollars were incinerated, though other US officials and experts were less bullish. The strategic aim is to deprive the militants of the resources they need to wage war by retaking their towns, cities and oil fields, and by American accounts, they have been succeeding.
Alongside the military efforts to disrupt ISIS' finances, the US Treasury and its European counterparts are pursuing a number of paths to cut the flow of cash to the group.
Still, said Mr Derek Chollet, a former top Pentagon official in the Obama administration: "I don't think anyone is going to declare victory now, nor should they."
The Pentagon wants to cut the number of US peacekeeping troops in Egypt's Sinai Peninsula, partly because of the growing threat from ISIS, an official said on Tuesday. Islamists have long used Sinai as a base. About 700 US troops participate in a United Nations operation established after Israel and Egypt signed a 1979 peace deal and agreed to a Multinational Force and Observers (MFO) mission to monitor compliance.
Pentagon spokesman Jeff Davis said the US remains "fully committed" to the MFO mission but wants to use drones and other high-tech tools to assume some of the riskier work.
US officials are also considering moving some US and international troops into a camp in the southern Sinai, far from their current base near the Gaza Strip.
NEW YORK TIMES, AGENCE FRANCE-PRESSE