What connection does President Obama draw between step three of his plan (Paragraphs 21-22) and improving the nation?

The connection that President Obama draws between step three of his plan and improving the nation is that it is vital for American citizens to be responsible and vigilant for the development of the nation.

Explanation:

President Obama in his speech addresses the people of the nation and conveys to them that without their vigilance, making America great again would not be possible. He states that if the citizens behave with more vigilance, the feat of an indestructible and unthreatenable nation can be easily achieved.