Section 349(a)(5) of the Immigration and Nationality Act (INA) (8 U.S.C. 1481(a)(5)) is the section of law that governs the ability of a United States citizen to renounce his or her U.S. citizenship. That section of law provides for the loss of nationality by voluntarily performing the following act with the intent to relinquish his or her U.S. nationality:
"(5) making a formal renunciation of nationality before a diplomatic or consular officer of the United States in a foreign state , in such form as may be prescribed by the Secretary of State" (emphasis added).
B. ELEMENTS OF RENUNCIATION
A person wishing to renounce his or her U.S. citizenship must voluntarily and with intent to relinquish U.S. citizenship:
appear in person before a U.S. consular or diplomatic officer, in a foreign country (normally at a U.S. Embassy or Consulate); and sign an oath of renunciation
Renunciations that do not meet the conditions described above have no legal effect. Because of the provisions of section 349(a)(5), Americans cannot effectively renounce their citizenship by mail, through an agent, or while in the United States. In fact, U.S. courts have held certain attempts to renounce U.S. citizenship to be ineffective on a variety of grounds, as discussed below.
Paragraph (5) of Section 1481 is NOT the only relevant clause.
Try reading paragraph (2):
“(2) taking an oath or making an affirmation or other formal declaration of allegiance to a foreign state or a political subdivision thereof”
Also, to repeat myself, you are referring to the statute in effect NOW and NOT in effect in the relevant time period.
For example, the wording “voluntarily performing any of the following acts with the intention of relinquishing United States nationality” in the introductory clause of section 1481 and modifying both paragraphs (2) and (5) was added in the 1986 amendments and did NOT apply to actions Obama may have taken in the late 1970s or early 1980s.
If Obama signed and submitted an official document with Indonesia in that time period to obtain or renew a passport he very likely by that action necessarily affirmed allegiance to Indonesia.
That would have resulted in the loss of his US nationality whether any consular officer knew of it or not.
I suspect that Obama kept up his Indonesia passport for some time even as an adult, perhaps using it to travel to Pakistan and perhaps also for the months in Bali when he said he was working on his book (when it appears he stayed longer than a normal tourist visa under a US passport would have allowed). It may have come in handy when applying to colleges to have a foreign passport to support admission by universities at a time when accepting more foreign students especially from third world countries was becoming in vogue.
If so, he likely didn’t tell Indonesia that he was maintaining a US passport on the side. But that he may have been lying to Indonesia doesn’t matter, when he signed and submitted the paperwork for his passport renewal in Indonesia because Indonesia did not permit foreign passport holders to obtain Indonesian passports, the submission he would have made under Indonesian law was likely sufficient to lose his US nationality as an affirmation of allegiance.