Interesting quotes.
I believe it was George Orwell who is credited with "Those who study history..." quote.
Whilst I tend to agree with you on your sentiments on US policy (and to a lesser degree UK policy), Its worth while remembering most superpowers in history have been reviled and attacked. (The Romans, the British- at the height of thier empire- all fought many battles to keep thier territories)
It doesn't necessarily follow that all that they stood for and achieved was bad, or thier intentions evil. I think only time will tell whether present US policy is for the better or not.
Back to quotations - Of the thousands of quotes available, it is easy to find one that has meaning in the present day.
For example

"History is the interpretation of the significance that the past has for us"
Johan Huizinga (1872–1945), Dutch historian

"History shows that there are no invincible armies"
Josef Stalin (1879–1953), Soviet leader.

"History ... is, indeed, little more than the register of the crimes, follies, and misfortunes of mankind."
Edward Gibbon (1737–1794), British historian

Isn't history wonderful.

EDIT
Wondering what was mean't by "Pax Roma". The Fontana Dictionary of Modern thought had this:

"Pax Americana
The concept of peace imposed by North American rule or, more broadly, the settlement of conflict on US terms and in accordance with US interests. A variation on the term pax romana, it has been used in recent years primarily with reference to crises in Central America"

Prehaps pax Americana would have been more approriate?