In a move that has not yet been widely enough noticed, the Libyan Transitional National Council a few days ago shut the Syrian embassy and recognised the Syrian National Council (which has recently unified virtually all the non-violent anti-Assad Syrian Opposition behind its banner) as the government-in-waiting of Syria.
This is an exciting development, and a move that ought to be followed up by Britain and by other European countries (and by the EU itself).
One of the things that the Syrian protesters now most want (they of course mostly do not want foreign military intervention) is precisely this: serious diplomatic sanctions against Syria, to delegitimise the Assad regime in the eyes of the world.
As was the principle with the anti-apartheid struggle, the prima facie weight should always be put on what the righteous indigenous want. This should be the default position of what those in solidarity with democracy protesters call for. In South Africa, back then, this was: economic sanctions. In Libya earlier this year, this was: a NoFlyZone. In Syria, now, it is: diplomatic (and some economic) sanctions.
Let's close the Syrian embassy in Britain (unless it is prepared to declare 'UDI' from its capital, as some Libyan embassies did during the uprising there), and make the bold move of recognising the SNC as the only legitimate government of Syria. The facts on the ground are that Assad doesn't govern Syria any more. He merely tries (and mostly, due to the extraordinary bravery of the bulk of the people, fails) to terrorise it.