If a foreign entity announces their intention to strike at and attack the United States or any of our allies, such is a de facto act of war. If they keep their intentions secret and it becomes known that they wish to attack us or do our citizens harm the same is true. It does not matter if they do not have the capability to carry out the threat at the time the threat is made.
If your neighbor threatens to kill you, you don’t wait until five days later until after he has bought the gun, loaded it with ammunition and kicked in your door to act if you value your own life. The right of America to defend herself and her allies follows these same dictates and it is not necessary for America to be struck first before we take action.
Does this mean that we rush to war at every insult of slight from every tin horned despot or dictator fuller of himself than is warranted? No. It does not. Each situation must be independently analyzed.