Can Failure to Register with Selective Service Prevent Attaining Citizenship?
One’s failure as a male applicant between the ages of 18 to 26 to register with Selective Services may very well be a disqualifying factor to apply for naturalization. If you fail to register on purpose and do this willfully, then, yes, that could be an issue insofar as becoming a US citizen. If it’s just an inadvertent omission, or it’s a mistake, or it’s not material and not willful, then it should not be determining factor.
There are procedures where you can actually explain to US Immigration of what happened, and this may be taken into consideration either favorably or not.