It may be that govt cannot prevent every single one of these things. Afterall, murder, rape and other crimes are still around.
“The power to declare war, including the power of judging the causes of war, is fully and exclusively vested in the legislature.” ~ James Madison, Father of the Constitution
“We do not believe in aggressive or preventive war. Such war is the weapon of dictators, not of free democratic countries like the United States.”~ Truman, Sept 1, 1950