Most people oppose the Iraq war and the War on Drugs because it is ineffective and too expensive. Many politicians, including Ron Paul, argued that war harms the economy because of the higher government spending. They do not have any moral reasons to oppose the war.
Government is funding a microchip implant, called the VeriChip. The VeriChip company holds a patent on the idea, so they lobby the government to mandate everyone to use it, just like the vaccination companies. The chip includes a tracking device that invades their privacy and self-government. Microchip implants have additional advantages, such as detecting the blood cocaine levels and the blood alcohol levels. The ease of detecting an illegal drug would raise effectiveness of the War on Drugs and the significantly ease the costs. Many conservative politicians would support it to fight the Drug war.
Let's suppose a new technology is invented that reduces the costs of war to a fraction. More people would likely to support the Iraq war because of lower costs. Because of the lower costs, conservatives would support it. They have no moral objection.
It is also perfectly logical for minarchists to enforce microchips on everyone to reduce costs of defence forces so government would be voluntarily funded. They install microchips in everyone's mind to reduce aggressive thoughts and thoughts about succeding the government. These kinds of minarchists are totalitarian minarchists, who proposes mind control. This is another proof that minarchism leads to totalitarianism.
Every government intervention should be morally objected, not weighed on an utilitarian basis.