Why did I have to make the choice if it was your roll? You decide. It's just a matter of finding a way in.
It doesn't matter, it still happened.
You changed governments swiftly and declared several areas in martial law because a large minority of your civilians didn't like the new government... It looks like a coup.
We did not establish diplomatic relations. I tried making them with you and you said no. Diplomatic relations go past waving and trying to make a deal - it means actually having an agreement on paper.
I'd say that's even worse... A massive line of troops close to the border, ready to all move at once that could launch a surprise attack.... No yeah that isn't something to be cautious about.
And I understand that they'd use their own IDs and passports but the problem is my government doesn't want to allow civilians from a seemingly hostile nation into it's borders. So there's that.
And if you'd like me to do that then it'll take me a day or two to go through everything.
Actually it is more of the other way around, using real life standards before there is any kind of high level diplomatic meeting hundreds, if not thousands, of civil servants have interacted beforehand and enormous coordination has occurred. Coordination on a level not possible without previously existing relations. Using this as your standard this would also mean that you bar services and goods from nearly every state in the world as such if you want to go by this I expect to see a third world country rp'd. If however you wish any semblance of advancement such policies will not work. It is common procedure for states to establish military infrastructure near their international borders and as such it is not out of the ordinary.
Finally the policies and actions of previous states have no relevance on your current state, the ruling stands unless you show the roleplay of your current state.