AMMAN - The al-Qaida-linked Nusra Front on Saturday denounced US-led air strikes on Syria, saying they amounted to a war against Islam and vowing to retaliate against Western and Arab countries that took part. 'We are in a long war. This war will not end in months nor years, this war could last for decades,' the group's spokesman Abu Firas al-Suri said. 'It's not a war against Nusra Front, it's a war against Islam,' he added in an audio message published on the group's social media network, its first reaction since the launch of the US-led strikes on Tuesday.