Who is they?
And "decades" means you are including the people who saw the mortgage meltdown coming.
The bottom line is you can't prepare after the surprise attack. Either you are ready at that moment or you aren't.
Also the things in the list of seven items are all things that can easily last for 1.5 years if not much longer. What is the big deal with buying toothpaste, soap, and other items in bulk. They aren't going to go bad. Likewise with the disposable lighters and small bottles of alcohol and salt.
Several years ago no one on this thread was suggesting getting those. I recommended silver when it was $18 an ounce and today it is over $85 an ounce. That was good advice.
However, we are much closer to all out war with a coalition of nuclear powers (Iran, Russia and China). The situation has changed. Now is the time to make sure you have water purification tablets which are about $0.15 each and basic medical supplies.