If I wanted to join the Libertarian Party of the United States (and perhaps many or all State parties), I would have to “certify that I oppose the initiation of force to achieve political or social goals.” That’s ridiculous. I would approve the initiation of force to achieve many political and social goals; for example:
The overthrow of an oppressive government of the United States, but only under conditions where success is likely. Otherwise, too many lives would be lost in vain.
Stealthy vigilantism where a known murderer or rapist has escaped justice on a legal technicality (e.g., the failure to give him a Miranda warning). Stealthy so that the vigilantes could execute justice without themselves suffering retribution from an unjust government.
A preemptive military attack on a foreign state or organization that is inimical to Americans, is actively developing plans to harm them, and has or is acquiring the means to execute those plans. This could include instances of great economic harm, such as shutting off a major source of oil or a key trade route.
I wouldn’t join the LP for another reason: It probably drains more votes from GOP candidates than from Democrat candidates. The GOP is far from perfect, but it’s better than the Democrat Party on most issues.