I dunno about "weapon of vengence"; such seems rooted in the past, and is better left to the Almighty.
No, this great big little piece of US diplomacy is all about shaping the future, along lines more polite, if not peaceful.

I imagine you refer to Romans 12:19, where Paul entreats:

"Dearly beloved, avenge not yourselves, but rather give place unto wrath: for it is written, Vengeance is mine; I will repay, saith the Lord."

But it's instructive to consider the PRECEDING verse:

"If it be possible, as much as lieth in you, live peaceably with all men."

This constrint is critical: if a man attacks me, then by definition it does not lie WITHIN ME to live peacably with him... he's arrogated that decision to himself.

Personally, I prefer the words of an older covenant:

"And I will lay my vengeance upon Edom by the hand of my people Israel: and they shall do in Edom according to mine anger and according to my fury; and they shall know my vengeance, saith the Lord G-D." [Ezekiel 25:14]

Vengeance may belong to G-d... but America is His instrument.