It would take a lot to convince me that they haven't been discussing this for years and have been waiting for the right time. The market is now loaded with others to do the delivery, which was probably one of the considerations. I'm sure another was how to announce it where they can blame someone else; at least to the point of ensuring some will defend them.
The minimum wage increase is their excuse. What they are doing is outsourcing their delivery to a 3rd party (GrubHub, Uber eats, etc). They wont have to pay them anything, the customer will. They are decreasing their head count, payroll, insurance, taxes, benefits, etc. They will lose some sales, but that wont even be close to their cost savings. They will easily make more money while selling their product at the same price. Any business would love to be in the same position.
Do you really think the US has any real concern about being attacked? There is plenty to say about US policies, both good and bad. Part of that is the nearly $1T per year spent on the military. I don't think you'll find many credible people who think attacking the US will be good for whoever does it.
Attacking the US has been, historically, one thing that tends to unite the country. We - Americans - like building shit and we like fighting people. We never stop building new weapons. But when there is no-one to fight, we fight each other. There is a huge social divide in the US right now. You want to fix that, attack us.
*Edit: spelling