The CPI-M Tuesday urged Prime Minister Narendra Modi not to join any unilateral American war against the ISIS, the Sunni insurgent group that now controls a vast territory."The Obama administration has been putting great pressure on India of late to join a US-led coalition against the Islamic State of Iraq and Syria," the Communist Party of India-Marxist said. "It may take advantage of Modi's presence in New York ... to make India fall in line with its plans. The (Indian) government must, under no circumstances, fall prey to these machinations. "It must never join any unilateral US initiative of this sort, no matter how strongly such an initiative is portrayed as defending 'humanity' against 'the forces of barbarism'."Any international response to the ISIS must have the sanction of the UN, without which it carries no legitimacy."