What fact or facts support a situation where trade is disadvantageous?

The facts that support a situation where trade is disadvantageous are the following:
1. Two countries will be having the same target market and they'll be identical.
2. The two countries will be limited when it comes to politics and the same times when it comes to geography.
3. The two countries will be producing the same goods.

The fact that the earth goes through natural cycles for example the ice age some scientists belive that it is just another cycle