Prime Minister Narendra Modi made Bhutan the destination of his first foreign visit. Now two weeks later, the foreign minister of the Himalayan kingdom, Rinzin Dorje, is in Beijing discussing the China-Bhutan border issue. The move poses a serious challenge to New Delhi because any negotiation on China-Bhutan border dispute is bound to affect India's border negotiations with China. Bhutan and China share 470 kilometres of border, which is also close to India's 'chicken's neck' -- the narrow Siliguri corridor which links the northeast.