The terror group has been driven out of an area the size of Ireland across Syria and Iraq after a sustained assault by government forces.
But defense and security experts are now worried the dramatic reduction in its territory could see the extremists escalate attacks on civilian targets in both Europe and across the Middle East.
According to figures compiled by IHS Conflict Monitor, ISIS controlled territory has dramatically reduced from 35,000 square miles in January 2015 to 26,370 square miles.
Earlier this year, IHS also estimated that ISIS revenue had dropped from £61.7million last year to just £43.2million in March this year.
And now Columb Strack, a senior analyst at IHS, is warning of a change in tact for the terror group.
He explained: 'Over the past 18 months, ISIS terrorist group has continued to lose territory at an increasing rate; Dailymail reported.
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