- Paris/San Bernadino happened because of ISIS.
- ISIS arose because Iraq was invaded.
- Iraq was invaded because of 9/11.
- 9/11 happened because of U.S. missile strikes on Bin Laden’s HQ, see White House daily brief, Wikipedia.
- The missile strikes happened because two embassies in Africa were bombed.
- See the above link for why the embassies were bombed.
You may quibble about this causality and ascribe extra causes; nevertheless, the point is that each reaction continues the chain. To break the chain, stop the reactions.
If you are Christian, consider these precepts: