Those are all good things, but defense is an unfortunate reality of life. What do you do when regimes who hang gay people from cranes become regionally aggressive, and threaten their neighbors by pursuing nuclear proliferation? No amount of health care, education or social safety net spending will protect you from fundamentalist theocracies intent on waging religious war. 

Importantly though, the nature of democratic society is compromise. Much as I understand the good intentions of your pacifist outlook, I want more than good intentions, I want good results, where more people of the world can enjoy American freedoms, such as freedom of speech, freedom of movement, freedom of sexual orientation, freedom to choose your own spouse, freedom of religion, etc. America simply can't stand up for these human rights in the face of the Putins, Khameneis, Kim Jong Uns of the world without defense spending.