Ron Paul is not interested in protecting us from terrorists. He has voted repeatedly against the Patriot Act, despite the pleas from the FBI and intelligence community to retain it and that it was vitally needed in the WOT.
You don't think that helps?
And you can't protect America's interests here and around the world by withdrawing our troops from every country on the planet (including Japan, Korea, etc.) and unilaterally declaring that you won't even honor defensive treaties with our allies (like Britain).
Did Paul say he would do that?
In the long run it's debatable whether it's worthwhile to put your troops in friendly countries (like South Korea and Japan) rather than staying on good terms with them and having them provide for their own security. Grown-up countries should defend themselves; it's one of the legitimate functions of a sovereign government, and it's reasonable for Japan and Korea to shoulder their share of the load.
Paul is a non-interventionist, not an isolationist. He favors diplomacy, trade, and defense; he just doesn't favor the US being the world's self-appointed policeman. A lot of patriotic Americans share his point of view.