Assertion: The war with China alerted Indian leadership to the volatile situation in the Northeast region.
Reason: Apart from being isolated and extremely underdeveloped, this region also presented India with the challenge of national integration and political unity.

Both the Assertion and the Reason are correct and the Reason is the correct explanation of the Assertion.

The war with China alerted Indian leadership to the volatile situation in the Northeast region. Apart from being isolated and extremely underdeveloped, this region also presented India with the challenge of national integration and political unity. The process of its reorganisation began soon after the China war. Nagaland was granted statehood; Manipur and Tripura, though Union Territories, were given the right to elect their own legislative assemblies.