Pinchas was a zealot and therefore he was the one person who was rightfully able to kill Zimri (as per the Halacha of Habo'el aramis kanaim pogiin bo).
But here is the bombshell: The Torah calls Pinchas a man of peace!!
"A zealot?" you ask, "does that not conjure up an image which is opposite of the man of peace - a man who was blessed with the covenant of peace and who will ultimately bring the geulah - the real peace?"
The answer is, PEACE is not only the end of a war - nor is it hairy hippies singing kumbaya (whatever that means). It is a state of harmony when all the pieces of the puzzle come together, when the symphony plays in unison. That is peace.
Peace is Totality = SHLEIMUS (same root as SHALOM); a whole.
With Zimri's blatant act of sin, he threw the Jewish nation into limbo. The only way to regain balance was to KILL HIM!!!
YES MY DEAR FRIENDS, THAT WAS AN ACT OF PEACE!!!
The HEILIGER KOBRINER is quoted in the NESIVOS SHALOM (path of peace) as saying that in our MILCHEMES HAYETZER, the worst thing we can do is to " MAKE PEACE"
That he says, is called "complacency" (I call it rolling over and playing "DEAD")
So if you are looking for real PEACE my brothers, then FIGHT, FIGHT, FIGHT!!!!!