Question

Military service in kaafir armies and working as a “chaplain” in those armies

What is the ruling on Muslims serving in the military of non muslim country ? What is the evidence for its permissibility or prohibition? And lastly, what is the status of a Muslim working to help those in the military to fulfill their obligations to Allaah while serving in the Army, Navy, or whatever?
Answer
Answer

Praise be to Allaah.

We put this question to Shaykh Muhammad ibn Saalih al-‘Uthaymeen, may Allaah preserve him, who answered as follows:

“Praise be to Allaah, the Lord of the Worlds. Military matters are problematic, because they involve helping these kuffaar to wage war against the Muslims or those who have entered into a treaty with the Muslims. If no such thing is involved, it may be advantageous for Muslims to work in these armies so as to learn their secrets and be aware of their potential evil. In other words, if working in these armies could be of benefit, it may be permissible, otherwise it is not allowed.”

On this basis, if a person works as a preacher or daa’iyah or imaam or muezzin, serving the Muslims and calling non-Muslims to Islam, then there is nothing wrong with this.

Islam Q&A 
Sheikh Muhammed Salih Al-Munajjid