Some comparative theology time I guess?
Notably, I never said ‘by the sword’ was the only way. There is definitely a history of a number of religions doing it though!
First, I am under no illusions that what a religions book (or common formal teachings) says necessarily matches what its stated followers actually do.
Judaism essentially forbids ‘recruiting’, and it is quite difficult to convert. Mainly because Judaism is essentially ‘this group of people have a special deal with god/are god’s special people’.
Christianity has very mixed message (especially depending on which version of the Bible!) with some explicit calls to convert others - but without any calls to violence associated with them I can see [https://www.biblegateway.com/passage/?search=Matthew%2028%3A...]. John the Baptist being a prime ‘doer’. Also, there are explicit calls to ‘turn the other cheek/not retaliate’, such as [https://www.biblegateway.com/passage/?search=Matthew%205%3A3...].
Which makes the crusades particularly crazy/insane of course. Jesus was clearly non-violent and didn’t want people going out killing each other over anything he was saying.
At the time, the Church (now Catholic Church) heavily controlled ‘the word’, by insisting everything be done in Latin - which they were then the gatekeepers for. They also meddled (or flat out controlled!) national politics, and this gave them immense power to control the narrative of ‘what god demands’ in ways that now clearly contradict what we can read ourselves.
Islamic teachings can be interpreted in many different ways, and there are at least 2 major schools of thought (Sunni/Shia), and two major regional differences. What is taught//practiced in most of the middle, and what is taught/practiced in Indonesia being clear differentiators, for example.
But the Koran and its Hadiths are generally relatively accessible, if one looks, and it’s not hard to find analysis of different elements of it online. Unlike the Bible, there are explicit calls for the devout to study it directly. Also, unlike the Christian Bible, it also tends to be less - chaotic and internally conflicting. Comparing Matthew and Leviticus would give anyone whiplash, for example.
For instance - Quran 9:5 [https://islam.stackexchange.com/questions/71323/what-is-the-...].
As to if it means believers must go to war with specific ‘irritating’ local tribes, or means all unbelievers, depends on who you ask. But most agree it means unbelievers in general. Many of the ‘problem’ groups in recent history with the west have explicitly used it to justify their attacks (among many others).
There are specific carve outs/exceptions for Jews and Christians (though also corresponding ‘give them no quarter unless they convert/behave as Muslims’ sections!), and in general the expectation is that for them to be protected they need to respect Islamic law and behave accordingly. Which isn’t really possible, for the most part, without significant changes in behavior/belief.
So depending on how ‘close to the book’ someone is being, and if sections are being ignored, depends on how much someone is going to believe/follow. Notably, Indonesia is widely seen is ‘Islam light’, but they do follow quite a bit of it (like how marriages work, expectations for women), that the west would struggle with. Middle eastern countries, communities in Pakistan, India, etc. tend to be the hardest core.
And once you understand the nature of the teaching, it is hard to not see the western way of life as being the personification of Iblis (the great satan - the tester of faith). After all, who wouldn’t want to chill out and drink beer, watch TV, and ignore the (often difficult) teachings of God? join us…, it’s fun! And don’t worry, there is no actual god anyway.
And like the old Christian Church during the crusades, government and madrases (religious schools) tend to be intermixed, which of course causes ‘problems’ similar to
the crusades.
Thankfully not to the full extent, right now anyway.