That's politics, and politicians who's allegiances are to themselves first, their sect/party thereafter, and have completely lost sight of the people they are supposed to represent with their sectarianism.
Fair enough...... but here in the UK, when things get bad, we assimilate into coalition. And so, although there will be a general election tomorrow, in difficulty there is a basic accord which rises above politics.
I will admit that assimilation & sectarianism is a growing problem in our country as well, that is why nothing gets done for the good of the country or it's citizenry...it is a divided nation sadly.
We divide here on many issues, and 'things' heat up...... but generally speaking we do live 'side by side' and work 'side by side' very well. My father-in-law is very anti-immigration, a 'send them home' bigot, a secular pagan, but before retirement he worked in a team with Sikhs, Hindus, Muslims and Nigerian Christians and I know that he got on really well with them. Now that's how strange our kind of assimilation is.
You have to define what you want that "togetherness" to look like first, having multiple cultures fighting for dominance, especially toxic ideologies of some cultures willing to commit violence to destroy your culture is not an acceptable situation.
OK..... I already touched on my definition above, but my attempt would be something like 'We travel, work and trade very well together, but our varying cultures and ideologies are separate and private within our separate communities.'
Of course, you're seeing where it fails, just now.
But it was failing in the 70s and 80s very badly. The Brighton, Guildford, Birmingham and other bombings were huge and horrific. I expect that people like you would have understood exactly what was happening back then in the UK, but many US citizens didn't understand it all. PIRA, UDR and many other sections were passing buckets around your bars etc and US folks were filling them, unaware that these sections were killing each other, and surveys showed that folks had no idea about any of the situation.
I don't expect that many understand about our problems with football violence. Some teams are Protestant supporters, other Catholic...... like Rangers and Celtic. Such games used to be very very fraut.
If you go into some pubs in SCOTLAND and speak, you could be welcomed, or quietly told that your pub is over the road. But these folks work together!
We don't even fully understand ourselves, so you've got no chance!