Long article. Here is the concluding paragraph.[] the Russian air campaign has an advantage over that of the Americans in that it has been launched in support of an effective regular army. The US never dared to attack IS when it was fighting the Syrian army because Washington didn't want to be accused of keeping Assad in power. The US approach has left it without real allies on the ground, aside from the Kurds, whose effectiveness is limited outside Kurdish majority areas. The crippling weakness of US strategy in both Iraq and Syria has been to pretend that a 'moderate Sunni opposition' either exists or can be created. For all America's fierce denunciations of Russian intervention, some in Washington can see the advantage of Russia doing what the US can't do itself. Meanwhile, Britain is wrestling with the prospect of joining the US-led air campaign, without noticing that it has already failed in its main purpose.