Wrong decision to apply for SG citizenship for my son?

[NWChicago]

My son is a US citizen, and in 2007 when we moved to Singapore from Chicago, we applied for SG citizenship for him, thinking we would live here for good. He has the Citizenship Certificate now. Is this exactly the same situation as someone born in Singapore, and subject to the NS Enlistment Act, application for Exit Permit, paying a bond...the list goes on.

At age 11, he definitely prefers the US, especially with the hot weather here aggravating his eczema.
Question:
1. What will you suggest I do? It seems silly, and makes me sound ignorant, but what I'm asking is, can we essentially drop the Cit. Cert and re-apply for PR?

I realize now getting him the SG PR would have been a better decision, since he would essentially be able to live in both the US and Singapore. If he decides to live in the US, he can easily drop his SG PR. If he decides to live in Singapore, he can just give up US citizenship, and be spared of the US heavy taxes. It seems to be extremely difficult for a male citizen to renounce citizenship. BUt what he has is the Cit. Cert. I thought I read on the back of the Cert. that my son will need to go through some oath-taking when he turns a certain age. So until then he is not a full citizen?

[sundaymorningstaple]

Did he get his citizenship by right of descent? Are either you or your wife Singaporeans? If so, he's screwed. Read the various posts by Mad Scientist throughout the Strictly Speaking Forum and elsewhere on this board.