From the first days of India's Independence, it was appreciated that the Sino-Indian borders had been left undefined by the departing British and that territorial disputes with China were part of India's inheritance. China's other neighbours faced similar problems and, over the succeeding decades of the century, almost all of those were to settle their borders satisfactorily through the normal process of diplomatic negotiation with Beijing.
The Nehru government decided upon the opposite approach. India would, through its own research, determine the appropriate alignments of the Sino-Indian borders, extend its administration to make those good on the ground and then refuse to negotiate the result. Barring the inconceivable -- that Beijing would allow India to impose China's borders unilaterally and annex territory at will -- Nehru's policy thus willed conflict without foreseeing it.
Through the 1950s, that policy generated friction along the borders and so bred and steadily increased distrust, growing into hostility, between the neighbours. By 1958, Beijing was urgently calling for a standstill agreement to prevent patrol clashes and negotiations to agree on boundary alignments. India refused any standstill agreement, since it would be an impediment to intended advances and insisted that there was nothing to negotiate, the Sino-Indian borders being already settled on the alignments claimed by India, through blind historical process. Then it began accusing China of committing 'aggression' by refusing to surrender to Indian claims.