2 relevant answers from the muslim "Ask The Imam" site:
Is it allowed to obtain United States Citizenship so that travelling for deen becomes easier?
Question 5193 from United States:
They require you to promise to bear arms for the country. The oath of allegiance is as follows: The Oath of Allegiance I hereby declare, on oath, that I absolutely and entirely renounce and abjure all allegiance and fidelity to any foreign prince, potentate, state, or sovereignty, of whom or which I have heretofore been a subject or citizen; that I will support and defend the Constitution and laws of the United States of America against all enemies, foreign and domestic; that I will bear true faith and allegiance to the same; that I will bear arms on behalf of the United States when required by the law; that I will perform noncombatant service in the Armed Forces of the United States when required by the law; that I will perform work of national importance under civilian direction when required by the law; and that I take this obligation freely, without any mental reservation or purpose of evasion; so help me God. If they require or ask you to bear arms against a muslim country, what should be the response. Their laws are against 4 marraige law of Islaam. Does the pledge cause any "Ilhaad" or any such anti-islamic view? Please answer according to Hanafi Fiqh.Answer:
1. If your intention is solely to facilitate easier travel, you are permitted to obtain US citizenship. Although the oath of allegiance is un-Islamic in nature, it will not be treated as an 'Islamic oath'. Therefore, you are not compelled to execute the oath.
2. If you are called up to bear arms against Muslims, you are not permitted to do so by Islamic law.
3. The pledge does not constitute Ilhaad.
and Allah Ta'ala Knows Best
Mufti Muhammad Kadwa
FATWA DEPT.CHECKED AND APPROVED CORRECT: Mufti Ebrahim Desai
To become a citizen of US one has to take an oath of allegiance. is it ok to take the oath.
Question 8471 from United States
The oath of allegiance is as follows: I hereby declare, on oath, that I absolutely and entirely renounce and abjure all allegiance and fidelity to any foreign prince, potentate, state, or sovereignty, of whom or which I have heretofore been a subject or citizen; that I will support and defend the Constitution and laws of the United States of America against all enemies, foreign and domestic; that I will bear true faith and allegiance to the same; that I will bear arms on behalf of the United States when required by the law; that I will perform noncombatant service in the Armed Forces of the United States when required by the law; that I will perform work of national importance under civilian direction when required by the law; and that I take this obligation freely, without any mental reservation or purpose of evasion; so help me God. They also ask on the citizenship form the following questions: If the law requires it, are you willing to bear arms on behalf of US? If the law requires it, are you willing to perform noncombatant service in the US Armed Forces? If the law requires it, are you willing to perform work of national importance under civilian direction? My question is can we answer yes to these questions? is there anything wrong in doing that. what should the answer be: yes or no? could you please kindly give an urgent answer. jazakallah.Answer:
As Muslims, we are duty bound to follow our lives strictly according to Shari’ah. Whatever Shari’ah allows us to do, we will abide by that and whatever Shari’ah has restricted us from, we will refrain from it. Hence, we are not allowed to obey anybody if it is resulting in the disobedience of the Creator, Allah. Nabi (Sallallaahu Alayhi Wasallam) said, ‘There is no obedience for the creation by disobeying the Creator.’ (Mirqaat vol.7 pg.217; Imdadiyyah).
Hence, keeping this in mind if one is forced to sign the above in order to become a citizen or the only way of attaining citizenship is by acknowledging the above, then one may sign it with the intention that Shari’ah and Deen will always be his yardstick and that he will never sacrifice any of the teachings of Deen.
and Allah Ta'ala Knows Best
Mufti Ebrahim Desai
So basically, the oath is non-binding.