Though Ron Paul doesn't classify the War on Terrorism as a war between sovereign nations or as a justification for the erosion of personal liberties he is likely the strongest anti-terrorism candidate.
Ron Paul supports violent retribution against terrorists. He supports accurately analyzing and evaluating any clear and present danger to the nation.
In retribution and defense he would use and/or hire military forces to eliminate potential threats and kill malicious militants. This method of not using all out invasion and occupation not only kills offenders, but also reduces the recruiting methods of terrorist organizations.
It is likely that the reduction in recruitments alone, Ron Paul would eliminate more terrorists than the entire war on Iraq has. The cooperation of foreign governments would be increased as the US would not be seen as a potential threat to their sovereignty, but rather as a nation acting in self, and indeed even mutual defense.
This method is less expensive but more complicated. However it is more efficient and does not rally entire populations of the world in hope that the US will suffer another disaster.
The military teaches us this logic, you must not only bomb the enemy tanks but also the factories so they can't make more tanks. Our current NeoCon policy bombs the terrorists....and turns nations into terrorist factories.
Ron Paul offers the only practical approach to preventing the further empowerment of our enemies while attacking the culprits directly.
You may hear it often, the military are not police, they are not investigators, detectives...or designed to manage civilian populations. We are using an anvil to remove a tumor which is better removed with a surgical blade.
Edit: Ron Paul raised more money from active military personnel than all other candidates, Democrat and Republican combined. No surprise.