@ Gan...
It doesn't need to be explained, It's Like this, { You're against Syria you die }
Being Hariri with the Opposition Party was very dangerous for them, It can cost them alot...We all know what Hariri is Capable having alot of Relations, Millions of People After him, These things it doesn't suit them...
Today i just saw an Interview with this Egyptian whom works for a daily newspaper in egypt, and he said " Before two month of Hariri's death, he was in Syria to meet Bashar El Asad, They had a discussion and Bashar offered Hariri to come back from his decision and be the Prime Minister again, Hariri Replied him: I can't there is alot of stress and tension and I prefer leaving anyhow am not doing my Job being Prime Minister, You Guys are telling us what to do, so I prefer leaving and staying with my Family, then Finally Bashar told him"Then your Responsible of Yourself"
The Egyptian guy didn't lie, he had a great Relation with Hariri, and when Hariri Came back to Lebanon the Egyptian guy had an interview with him in a magazine called " Al Shabaka " and Hariri told him everything....
So having a bad Relation with Syrian Government and Joining the " Opposition Party " whom else then Syrian could have the power and the balls to Kill our Great man.....
And Gandalf if you read my posts in some pages there are many other reasons, as i said, Syrian have murdered alot before, so i wouldn't be surprise if they were after Hariri's murder.......