Something was wrong. Beirut's streets were deserted, save for a few soldiers and frantically honking taxis. Barbed wire and tanks blocked access to downtown.

I had just arrived from Syria with my Italian wife Francesca and two friends. We had time for a jaunt into Lebanon, so we'd come. We'd seen nothing to alarm us in the news, and the warning on the US embassy's website was similar to its advice on Syria - which had been spectacularly inaccurate.