One of the most powerful forces in the Middle East - set up to oppose Israel and designated a terrorist group by the US and EU. But over the last year, Lebanon's Shi-ite Hezbollah militia - heavily backed by Iran - has begun to change the military balance in the SYRIAN civil war in favour of the Assad regime. .Sign up for Snowmail, your daily preview of what is on Channel 4 News, sent straight to your inbox, here: mailing.channel4.com/public/snowmail/remotebox.jsp Missed Channel 4 News? Catch up on the last seven days here: www.channel4.com/news/catch-up/ Channel 4 News weather forecast, with Liam Dutton: www.channel4.com/weather/ All the latest blog posts from the Channel 4 News on-screen talent: blogs.channel4.com/news/