Assuming you are an American citizen, the relevant law is something like:
Nothing contained in this title [regarding mandatory military service] shall be construed to require any person to be subject to combatant training and service in the armed forces of the United States who, by reason of religious training and belief, is conscientiously opposed to participation in war in any form. Religious training and belief in this connection means an individual's belief in a relation to a Supreme Being involving duties superior to those arising from any human relation, but does not include essentially political, sociological, or philosophical views or a merely personal moral code.
take from Welsh v. United States, 398 US 333 (1947)
In particular, you must show that your position is a deeply held moral conviction opposing war in all circumstances, not just opposition to a particular war. GILLETTE v. UNITED STATES, 401 U.S. 437 (1971).
For reasons similar to Barbarians shouldn't win, I can't endorse trying to fake being a pacifist (additionally, the false statements you would need to make would be separate crimes from failure to report for service).
But if you really oppose all war, you'll need to justify it with testimony (written or oral), and your prior behaviors won't be all that relevant. Pr(excused from service as conscientious objector | my prior conscientious objector behavior) is low. Pr(excused from service as conscientious objector | compelling descriptions of your relevant personal beliefs) is orders of magnitude higher.
Based on this, it appears that only overt religious signaling is acceptable for being declared a conscientious objector. I don't believe in any Supreme Being, so I don't know where that leaves me in this description. I am ideologically and ethically opposed to war, and in particular to the military experience of serving in the American armed forces. I don't think it would be insincere or any sort of false testimony risk for me to claim that I am opposed.
My post is about what one should supply as "testimony" in your comment. It doesn't look like y...
Suppose that you believe larger scale wars than current US military campaigns are looming in the next decade or two (this may be highly improbable, but let's condition on it for the moment). If you thought further that a military draft or other forms of conscription might be used, and you wanted to avoid military service if that situation arose, what steps should you take now to give yourself a high likelihood of being declared a conscientious objector?
I don't have numbers to back any of this up, but I am in the process of compiling them. My general thought is to break down the problem like so: Pr(serious injury or death | conscription) * Pr(conscription | my conscientious objector behavior & geopolitical conditions ripe for war) * Pr(geopolitical conditions ripe for war), assuming some conscientious objector behavior (or mixture distribution over several behaviors).
If I feel that Pr(serious injury or death | conscription) and Pr(geopolitical conditions ripe for war) are sufficiently high, then I might be motivated to pay some costs in order to drive Pr(conscription | my conscientious objector behavior) very low.
There's a funny bit in the American version of the show The Office where the manager, Michael, is concerned about his large credit card debt. The accountant, Oscar, mentions that declaring bankruptcy is an option, and so Michael walks out into the main office area and yells, "I DECLARE BANKRUPTCY!"
In a similar vein, I don't think that draft boards will accept the "excuse" that a given person has "merely" frequently expressed pacifist views. So if someone wants to robustly signal that she or he is a conscientious objector, what to do? In my ~30 minutes of searching, I've found a few organizations that, on first glance, look worthy of further investigation and perhaps regular donations.
Here are the few I've focused on most:
Center on Conscience and War
Coffee Strong
War-Resister's International
The problems I'm thinking about along these lines include:
I'm curious if others have thought about this. Good literature references are welcome. My plan is to compile statistics that let me make reasonable estimates of the different conditional probabilities.
Addendum
Several people seem very concerned with the signal faker aspect of this question. I don't understand the preoccupation with this and feel tired of trying to justify the question to people who only care about the signal faker aspect. So I'll just add this copy of one of my comments from below. Hopefully this gives some additional perspective, though I don't expect it to change anyone's mind. I still stand by the post as-is: it's asking about a conditional question based on sincere belief. Even if the answer would be of interest to fakers too, that alone doesn't make that explanation more likely and even if that explanation was more likely it doesn't make the question unworthy of thoughtful answers.
Here's the promised comment:
Stated another way: