As a part-time libertarian, one of the frustrating parts of the pandemic has been discovering how many people need the nanny state to step to stop them punching themselves in the face. Near the start of the pandemic, I thought the most intrusive state powers would barely be needed. Why would you ever need to make a vaccine mandatory? What rational person would refuse a lifesaving medicine offered to them for free? We…
...that is why I could never be a libertarian. People have repeatedly proved themselves unwilling or unable to live up to the libertarian ideal of behaving "rationally."
Libertarians believe that force should be applied to person A to protect person B from person A in certain circumstances.
If person A wants to punch person B in the face, restricting person A by force is perfectly consistent with libertarian values.
If person A threatens to infect person B with a deadly disease due to refusing a vaccine, then a vaccine mandate has some justification under the same ideals. The devil will be in the details (e.g., how deadly is the disease, etc).
It's also why a carbon tax and many other measures are not inherently inconsistent with libertarian values on a first principles examination.
But for some reason, libertarians in practice tend to dislike these policy proposals, even though they can follow in principle from the founding axioms. I attribute that to group-think and a general disbelief in the existence of negative externalities, not to a problem inherent in libertarianism.