I'm trying to understand the English in this article (bolding mine):
“I think it was a genius action from Lula da Silva” said Mujica in an interview with the Brazilian daily Folha de Sao Paulo, when he argued it was a “gross mistake” of the international community to isolate Ahmadinejad.
“The more you fence in Iran, so much harder it will be for the rest of the world. What Lula da Silva is doing is something which I consider simply brilliant. Life has taught me that you can’t surround, fence in someone. It’s a mistake. This forces the other side to react, to fight back…The world does not need any more wars. It needs solutions, ways out to this kind of situations”, underlined the former guerrilla leader.
What does the sentence mean, The more you fence in Iran, so much harder it will be for the rest of the world.? I guess to fence in means to isolate? But as for the second part, so much harder it will be, what is it that is harder?