Being displaced from your home country does not give you moral shielding for killing the leaders of another. In fact, I would argue that being displaced from your home means you owe a debt of gratitude to the countries that take you in, which makes bad behavior in them more often reprehensible.
If something terrible happens to you in your life, you don't get to just take it out on random people. That goes doubly for those reaching a hand out in assistance.