As far as the enlightenment, I think that policy was an error unique to the Russian church. Can you source a single church father that supports such an idea or any generally accepted council calling for violent persecution of heretics?
The word "Ecumenical" means "Of the civilized world" and was a reference to the Byzantine Empire - carrying on the tradition since Julius Caesar's De Bello Galico that the Roman Empire was civilization, and the outsiders were barbarians. Hence the "Ecumenical" Patriarch of Constantinople (The Imperial Patriarch of Constantinople or the Byzantine Patriarch of Constantinople).
The "Ecumenical Councils" were called that because they became the binding law of the Roman Empire, and they were politically mandated on the citizens.
The oldest code of law from the Byzantine Empire that we have, that I know of, comes from Saint Emperor Justinian, "The Justinian Code", or more specifically, the Corpus Juris Civilis. The very first law in the Codex says that Christianity is the law of the land and all citizens are required to uphold the Church's Faith (that is, the Faith of the Empire).
To this day that's part of the reason why the Oriental Orthodox are so hostile to Chalcedon, because of the (often times bloody) persecution of their Saints. One example is Saint Samuel the Confessor in the Coptic Church, where Byzantine soldiers were visiting monasteries to make sure that the monasteries were complying with Chalcedon. Saint Samuel refused, and when he refused, the Byzantine soldiers beat him up so badly that they punched out his eye.
We also know for a historical fact that censorship of heresies were rampant in the Byzantine Empire too - the fact that so much of Saint Severus of Antioch's writings only exist in fragments is a testament to that.
That's why heresies were such a big deal at the time - if you got an Emperor who was a heretic, have fun with that - he could easily kick out Bishops he didn't like and persecute you if you disagreed with him.
This principle - probably originating from a combination of the Old Testament's texts and Pagan Rome Jurisprudence (There was no separation of Church and State in the Ancient Pagan Roman Empire either, we still have the alleged text of Saint Cyrpian's legal proceeding, before his martyrdom, preserved in the Church's tradition -
https://ritabay.wordpress.com/2014/08/08/friday-miscellany-the-trial-of-st-cyprian/ as an example of it)
- continued onwards not only with Russia, but also even when Greece finally got it's independence from the Ottomans after World War I with the whole Calendarist controversy, when Patriarch Meletius IV changed the Old Calendar and made that the binding law of the land. The Old Calendarists still talk about the violent persecutions they went under today.
I don't see where God says for Israel to invade other territories to convert the gentiles by force.
You ever read the Old Testament? After travelling in the Desert for 40 years, the Israelites were told by God to subdue the Canaanites living in the Promised Land, minding their own business. Read Joshua 6-12.
There's no conversion by force, sure. But I see that as such a miniscule issue considering the Old Testament has God commanding religiously motivated conquest and the Christian Empires made the Church the law of the land, essentially legally forcing conversion.