Actaea

I'm actually counting on the fact that "there are no atheists under fire."
Based on my personal experience, I can say that they might exist, but I haven't met any.
So, I'll think about it, of course. But you should also think about... easing the requirements for potential allies. Maybe a more tolerant attitude towards religiosity would be useful for you. Just in case.

Therefore, I see no reason not to invite my socialist comrades to negotiations.
I invite The Armed Republic of Sciencecracy and The Colony of Aghar to visit my hospitable country with its stunning nature. I happen to have a country residence for important negotiations with an appropriate level of security. There will be an opportunity to discuss the details of the alliance agreement (military alliances can be different), and if desired, to sign it. I also invite the Minister of Education of Sciencecracy (or whatever you call him) to come. I have some thoughts about another document.

In general, I have sent the official invitation, and whether you come or not is up to you.