E. Dual Citizenship and Dual Allegiance

Exception

A Filipino may not divest himself of Philippine citizenship in any manner while the Republic of the Philippines is at war with any country [Section 1(3), C.A. 63].

Loss of Philippine citizenship cannot be presumed. Considering the fact that admittedly, Osmeña was both a Filipino and an American, the mere fact that he has a certificate stating that he is an American does not mean that he is not still a Filipino, since there has been no express renunciation of his Philippine citizenship [Aznar v. COMELEC, G.R. No. 83820, May 25, 1990].