Lets keep this little caveat in mind...Trump just proposed a huge expansion in military spending. A few things from that:
1) That doesn't actually send a message to rest of NATO that they need to step up, because the U.S. isn't. It actually sends the exact opposite message.
2) The entire premise of the decades long military spending that we do, is to make the U.S. THE predominant military force on the planet. To maintain that...you don't want other countries increasing their military spending.
3) This is the essentially the NRA mentality on a global stage. More guns, tanks and bombs for everybody! If the entire world spent 3%+ of its GDP on military expenditures...we will have a lot more conflicts..not less. The global economy will contract because military spending provides no other economic benefit after its spent. Heck, if its actually used, it dramatically decreases economic output somewhere in the world (the place being bombed).