Because he's trying to convince you that it's clean water but the truth is, it's not. He might trying to convince you to jump there so that you get dirty and he laugh because you fell on his trap/prank.
There can be many benefits and down sides to this, in return for helping these countries you gain an ally. Although you have to spend your own money. All in all it is worth it in the end because you have another country you can trust.
