Are Believers Sanctioned By Scripture To Carry Weapons And Fight In Conflicts

What does the Bible have to say about Christians and Messianic Jews participating in armed conflict? Is fight in a war self defense or defense of loved ones and/or neighbors? Why did Yeshua tell the Disciple's to carry two swords? What will you do in the coming conflict? There was some popping and clicking during this episode which turns out has been a Skype issue.