I believe it is the natural right of every man woman and child to live free from initiatory violence and fraud, and that the only proper exercise of violence in human society is the defense therefrom. To speak of these values initially sounds quite reasonable to many.
Even amongst those who have accepted this theory as their mantra, there exists great hesitation to carry it through to its ultimate logical conclusion. That being, if one has the right to use violence to defend themselves against initiatory force, and the government exists solely to initiate force against the populace, and refuses to stop its predations when we ask politely. Then the reasonable man is compelled to do something most see as quite unreasonable.
To violently overthrow that institution. To take up arms against his government and kill its agents, and stop them by force.
A free man need not ask permission. He does as he sees fit. If others violently interfere with his peaceful activities, whether that criminal be wearing a bandana, a badge, or suit, then he defends himself with whatever level of force is necessary. Though he may take no pleasure in it, he ends lives if he must.
You may choose not to fight, you may choose to delay your fighting in hopes of fighting at a more advantageous time, you may choose to support those who fight in other ways, you may even choose to fight on the other side. But on your list of options does not exist a choice to avoid the war entirely. The war has been brought to you against your will.