The obvious perpetrotor????? If you think that the decision to go after these 4 specific guys is political, then your just another whacky pedestrian on the Arab street. They went after these guys because of the evidence. No doubt the evidence went cold when on the path to Nassrallah but he was involved.
15 police officers killed in Colombia helicopter crash (Reuters)
from the article: UN tribunal names Hezbollah suspects in Hariri assassination