MOSCOW - The fight against Islamist militants in Syria and Iraq should only be carried out in compliance with international law and with respect for the territorial integrity of these nations, the Russian Foreign Ministry said on Thursday."It is essential to fight this evil in strict compliance with the practices of international law, UN Security Council resolutions and the UN in general... and with strict respect for the territorial integrity of Syria and Iraq," ministry spokesman Alexander Lukashevich told a news briefing.US President Barack Obama said on Wednesday he had authorized US airstrikes in Syria and more attacks in Iraq in a broad escalation of a campaign against the Islamic State militant group.