A number of options have been discussed and suggested (and some of them have been implemented as well) for preventing the spread of ISIS (Islamic State of Iraq and Syria), especially as it threatens the security of superpowers like the US and emerging powers like India. The more frightening aspect is the ability of ISIS to attract thousands of foreign volunteer and resources.
Firstly, a coordinated strike against ISIS bases is warranted to take out their strike capability. The policy of attrition can also be employed by specifically targeting their top brass, using the Marines or Green Barrettes. Such a strike should ideally involve forces of various countries from around the world, namely the US, France, UK, India, China, Australia, etc.
Secondly, it is necessary to plug the flow of resources and volunteers to ISIS. Senator Ted Cruz has suggested that allegiance to ISIS should be treated as renunciation of American citizenship, thereby neutralizing the threat of these sympathizers from carrying out terrorist activities after returning home. The flow of finances should also be tracked and stopped, crippling their resources.
Thirdly, a long-term solution should be thought of and put into action. The islamic world has been at war due to Shia-Sunni conflict, and the imposition of foreign powers in the Middle East has only worsened the situation. Providing arms to Iraqi Security Forces is not enough. Bringing the disgruntled sections into the mainstream may prevent them from defecting to ISIS.