NATO allies need to live up to their obligations
If the Europeans would do what they are supposed to do on military spending they would not be getting grief from Trump and they would also be safer and have a greater deterrence from aggression by Russia and Others. Trump is not the problem. They are not holding up their end of the deal. Some of the allies have allowed their military readiness to slip to the point of impotence. Mainly Eastern European countries who feel under the greatest threat and the UK are the only ones coming close to their obligations.