If the Government weren't to oppress the united states it would all fall to chaos. The thought of the government letting us do what we want to do all the time and have our own "free will" would be ridiculous. If we had such "liberties" then no one would be safe and we wouldn't have laws. Oppression in most cases will lead to safety.
Oppression has, Throughout history, Worked effectively: however, It often is left with a stagnant underbelly of those neglected by the government and abused by them. In short, With this form of governing the state, It is beyond a reasonable doubt that the people will rise to overthrow the government and collapse/anarchy would grip the nation and leave it either reborn or in ruins.
List of other oppressive government: Nazi party, Hirohito's hermit kingdom, Stalin's government, Lenin's government, ISIS, Karadzic's rule, Xi's government
All of them definitely did not provide security to the world's peace, Let alone their own. My opinion in regards to how oppressive a government should be, Is that moderation is the key. You cannot have a government that is too oppressive (eg Stalin) or too lenient because neither both will work. We need to find where both meets in the middle and use common sense and our conscience to decide