Explanation:

If a national emergency is declared on ground of external aggression, Fundamental Rights under Article 19 will get automatically suspended. Besides, the enforcement of any fundamental rights, except Article 20 and 21, can be suspended as specified in the Presidential order.

In the event of emergency, state assembly will not get dissolved. They will also have the power to legislate on state subjects. But the law enacted by it shall be subject to the law made by Parliament on the same subject. It also means that the distribution of powers between Centre and States is automatically suspended and there emerges a full-fledged unitary State.