The Author has a view that US will cancel the agreement if India tests again. It can happen as "Both parties have a right to terminate the agreement by giving a one year notice."
Author has incorrectly assumed that France and Russia will toe US line in the NSG. India is too big and responsible power for that to happen.
The fear of Author(he must be a BJP supporter} stems from the fact that as a wishful thinker he is hoping Modi (or similar) person becomes India PM and India does what Gujrat did. In such a scenario US and the World will declare India a rogue state (similar to denying Modi US visa) and thus sanctions. A REAL POSSIBILITY.