Most of its doctrines presume a governmental body that will enforce its punishments against the populace, both believers and unbelievers.
That is exactly right. To get a better idea of how serious Islam is about this I will let Islam speak for itself.
Its mandate is the reform of the whole world.
Such a religion cannot be indifferent. It cannot be without a law of jihad. In the same way,
its government cannot
be without an army. While
the scope of Christianity is extremely limited, that
of Islam is extremely wide. While
Christianity does not cross the frontiers of advice,
Islam is a religion which covers all the activities of human
life. It has laws which govern the society, economic laws, and political laws. It came to organize a state, to
organize a government.
Excerpt from The Holy War of Islam and Its Legitimacy in the Quran
Ayatullah Morteza Mutahhari
Qur'an:8:39 "
So fight them until there is no more Fitnah (disbelief [non-Muslims]) and
all submit to the religion of Allah alone (in the whole world)."
Qur'an:9:29 "
Fight those who do not believe until they
all surrender, paying the protective tax in submission."
Qur'an:9:5 "
Fight and kill the disbelievers wherever you find them, take them captive, harass them, lie in wait and ambush them using every stratagem of war."
Qur'an:8:39 "
Fight them until all opposition ends and all submit to Allah."
It is spelled out very clearly where the koran stands on the issue of other faiths. Even the most moderate muslim wants everyone to submit to Islam whether he is willing to kill for it or not.
Some Muslims have let go of that belief and are willing to tolerate a secular government.
Unfortunatly these muslims would be seen as apostate. And the result of apostasy in the koran is death.
Qur'an 4:89"They wish that you would reject Faith, as they have, and thus be on the same footing: Do not be friends with them until they leave their homes in Allah's Cause.
But if they turn back from Islam, becoming renegades, seize them and kill them wherever you find them."
I hope this clears things up for you. The koran is very clear on what it intends to happen to all non-muslims.