Why are protests in Middle East way more effective than here?

Photograph: Ian Langsdon/EPA

500,000 protest cuts in London, and this is inspiring indeed.

But the protests in the Middle East / North Africa (MENA)have been vastly more successfully in forcing change than those held in the US / UK. Most of the MENA protests, which have toppled governments, have been predominately nonviolent too, just like here. So why have they been more successful while our protests are mostly ignored by the powers-that-be? Some of the anti-Iraq war protests were huge and while they may have led to some changes in US war policy, they’ve had nowhere the impact that the MENA protests have.

Why is this?