But, it is the people responsible for their own safety and security. The Supreme Court has routinely upheld it is the responsibility of the individual citizen and the police are under no duty to protect you; even in uniform, even on the clock.
However, the wars we are fighting today are not against conventional forces. If we we wait for the Reds to invade....don't hold your breath.
That said, the military is for the defense of the homeland in cases of insurrection and attack. That does not mean the attackers have to be ones that follow the Geneva Conventions - fall under competent authority and wear identifiable uniforms.
The state should be allowed to call up the militia, to include the National Guard, for repelling attack. To call up Active Duty and Reserves, should be Congress.
That does not give the militia/NG/military the right to usurp Constitutional Rights of the individual citizen. The police should not be a para-military force, nor should the military be a police force.
It's either "terrorism" and an act of war, or it's a crime. Maj Hasan (spit) is either guilty of an act of terror as an unlawful combatant, or he is guilty of workplace violence akin to any other common criminal. You (general; not you) can't bitch and complain that the police are being too militarized and expect them to combat the likes of the Boston terrorists and then turn around and say 'oh the National Guard shouldn't be here because they're not the police,' and then sit idly by and do nothing.
Do I think the citizenry (read unorganized militia) needs to be involved? Yes. Do I believe they should just be off willy-nilly to play army-man in the streets of Boston?
No. Once a situation arises and the public takes to guns, they should be organized under competent authority. Hence Article I Section 8 of the Constitution reserves the right to the States to appoint officers and train the militia.
Not only is "unity of command" (one of Mattis' flat ass rules by the way) good tactics and good discipline, it increases the odds the situation will be resolved effectively.
As an aside, I don't have a problem with the average citizen owning "military hardware" that is not detrimental to national security (for example cypto, nukes, advanced radar etc - things that if fell into foreign hands would compromise our war effort and negate our force multipliers.). In other words, I see no problem with people owning machine guns, mortars, grenades etc. But I do think they should be properly trained and certified before purchase.