The House of Commons Defence Select Committee warned that the terrorist group, like Al Qaeda before it, could transform into an international movement with off-shoots if squeezed out of Raqqa in Syria and Mosul in Iraq.
"The UK and coalition's strategy to counter Daesh [another name for ISIS] is predominately focused on Iraq and Syria and relies on the removal of territory from Daesh in order to eliminate it. That is a necessary, but not sufficient, strategy.
"Our counter-Daesh strategy should be as effective in Nigeria, Afghanistan or Libya as it is in Iraq or Syria. There needs to be a grand strategic discussion about the threat posed by Daesh and how we can defeat it," it added.
The UK has been taking part in air strikes against Islamist militants in Iraq since 2014 and Parliament authorised their extension to Syria last year.
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The committee found there had been 550 Royal Air Force (RAF) missions in Iraq since December 2015 and 65 in Syria.
Julian Lewis, the Conservative MP who chairs the committee, said the UK must focus on the long-term risks.
"If Daesh transforms itself into an international movement or a network of affiliates - like al-Qaeda before it - which can survive the loss of territory - the UK government approach will need to adapt," he said.
"For example, if Daesh is defeated in the Middle East but then grows strong in Africa, the current strategy will require major revision. Assuming Daesh is squeezed out of both countries, we have to focus too on what happens next - both in other countries to which Daesh may migrate and in Syria especially where there is no shortage of other Islamist groups, just as dangerous, which are planning to take control," he added.