The two of you signs a treaty

A treaty is quickly drawned up. The parchment where it is written on is very lengthy, but covered few important part. One, the treaty will last for twenty years. That may looked short, but in the current moment, it is enough. Second, the two nations will not attack each other, but instead will come to an aid if the other is attacked. Third, the two nations will coordinate economic activity to be mutually supporting.

Jan looks at the parchment. "Why mutually supporting?"

"Because, it will bring us closer than my marriage to Sonya will ever will."

"Explain."

"A marriage will serve to bind us for two, or three generations at most. If the government falls, and is replaced with another one, it cannot be depended anymore. But economy? It is less visible, but more important. You depend on us for food. And we depend on you for metal, and coal, and their products. We have knives pointing toward each other throat. It is easy to see when one is trying to betray each other, don't you think?"

He nods.

It is an easy concept to understand and to accept. You would provide something to him, and he would provide something to you. And it goes beyond that. If you want to backstab him, it would require making such a preparation that it would be noticeable to him. After all, it's inconceivable to sell him food during autumn, only to attack him in the spring. You need to **** his food supply first so that he wouldn't be prepared. The same logic applies to Jan. Plus, by having the economic activities interlinked, you're proposing to make it more expensive to betray each other, instead of, attacking another country.

"How about if war is waged on the basis of religion, or nationalism?" Jan asks.

"When that happens, it wouldn't matter if we're family or not anyway." You shrug before giving him a pointed look. "When someone wants to go to war, it's simple enough to come up with a pretext. This treaty intends to make it difficult for us to wage war on each other, not impossible."

"Fair enough."

"So, shall we sign it?" you ask.

Without saying much, Jan signs his parchment.