Highly hypothetical. Not much to contribute here.
Three points :
1. Nothing in this World is permanent. Everything is subject to change and that is the law of nature. What matters is, how to adapt to the change, and further more important than that, your ability to understand the change.
2. Nation-state is relatively a new concept. When it comes to country-to-country relations, it would be foolish to assume that it's basis is 'friendship'. Relations are built based on mutual benefits. That's how one should perceive it.
3. There is a huge difference between bureaucratic level of negotiations and business delegations.
Now, as I said, relationships are based on mutual benefits. Nobody cares what is your nationalistic agenda. Progressive thinking people are perfectly happy to interact with you, as long as there is a benefit in that. Nobody is going to ask you what you do at your home as long as you have something to contribute. That's the nature of relationships across the World, take the example of KSA and USA.
About an year back, I had an opportunity to go to Tehran as a part of FICCI delegation. I was the youngest member there. All the discussions that happened were centered around trade and profit margins. Nobody gave a damn about KSA or USA or Russia etc. etc. , straight down to business.
Now, if someone there had been stupid enough to talk about Shia and Sunni and why India has relations with both sects, then he would have been served accordingly, no questions about that. It's just that sensible and experienced people have the ability to set aside these differences and work together for the sake of greater good.
Hope you get the drift