1) For takfir to be declared, the nullifiers of Islam must be known. Allah Subhanahu wa Ta’ala says:
“Allah does not lead a people astray after His guidance has been given until He makes clear to them wherein error lies.” [at-Tawbah 9: 115]
Sheikh Muhammad ibn Abdul Wahab – Rahimahullah – gathered ten actions
that negate one’s Islam (Nawaqid ul-Ashr), the eighth one of which
states:
“Assisting the disbelievers (against the believers) (Mudhaharatul
Mushrikeen) and supporting them against the believers is one of the
actions that negates of one’s Islam…”
Thus, it is generally and widely known that one of these nullifiers
of one’s Islam is supporting, aiding or allying with the kuffar against
the Muslims. Allah Subhanahu wa Ta’ala says:
“Obey, follow and give allegiance only to that brought to you
from your Sustainer, and do not obey, nor follow nor give allegiance
to those who are Awliya’ besides Him.” [al-Araf 7:3]
“You will not find any people who believe in Allah and the
Last Day, making friendship with and loving those who oppose Allah and
His Messenger, even if they are their fathers or their sons or their kindred…” [al-Mujadila 58:22]
In addition, as Sheikh Abdullah ibn Humaid said:
“Whoever expresses Tawalli towards the disbelievers (Tawalli Kuffar)
and supports and helps them against the believers, then such
constitutes apostasy by one’s (proceeding) actions. It is obligatory to
apply the rules of apostasy upon such a person as is proved by The
Book, the Sunnah and the consensus of the scholars.” Ad-Durrar 15/479
Furthermore, Sheikh Abdul Latif bin Abdur Rahman bin Hassan Aal-Sheikh said:
“Whomsoever helps the disbelievers or brings them to the country of
Ahl Al-Islam, then that person is clearly an apostate.” Ad-Durrar 8/326
Thus, we should be in no doubt that if a Muslim chooses to aid, ally
themselves with, the kuffar against the Muslims then they have negated
their Islam.
2) Since we judge someone by what is apparent, it is apparent that if
a Muslim joins the Armed Forces or the Police of the kuffar, and wears
the uniform of the kuffar, then they have sworn allegiance to the
kuffar and/or to some Taghut of the kuffar – such as a President, some
nation-State, or some kaffir leader – since such allegiance is a
necessary part of joining and belonging to such kaffir organizations. In
addition, a Muslim pledges thereby to uphold the fallible manufactured
laws of the kuffar and to obey the kuffar.