Fighting Islamic State has been a priority for the US and Britain ever since the group began beheading western hostages while rampaging across Iraq and Syria in 2014. Recent days have seen both a marked intensification of that campaign and vicious reminders that even under pressure the jihadis are alive and kicking.  If confirmed, the targeted killing of Mohammed Emwazi will be a tactical and psychological achievement for the anti-Isis coalition, though it will have a greater impact in London and Washington than in the Arab world. “It shows we have killed one of their champions,” said one Whitehall official. But it is hard to see much practical effect on the group’s operations.  Related: 'Jihadi John': Pentagon to hold briefing on Emwazi air strike – live updates  The capture of the strategic Iraqi town of Sinjar will probably turn out to be far more significant than the demise of one sinister executioner with a high media profile. Holding Sinjar could help open the way to Mosul, whose sudden fall precipitated the Isis declaration of a caliphate in Raqqa, in north-eastern Syria. Fallujah and Ramadi beckon too, though some way down the line of what looks like a long haul.  Sinjar demonstrates again that Kurdish troops are the most effective force for fighting Isis on the ground. US and allied air attacks – 2,700 in Syria and 5,100 in Iraq since September 2014 – have become routine but they have had a quietly cumulative effect, disrupting supply lines and forcing the jihadis into risking open communications and movement.  Strategy and spin are closely connected in this campaign. John Kerry, the US secretary of state, made clear in a hastily arranged speech on Thursday that a more concerted effort was now under way – apparently galvanised by Moscow’s dramatic military intervention in Syria in late September. Russian airstrikes are ostensibly aimed against Isis but in fact are targeting any rebel forces fighting Bashar al-Assad.  Kerry said Barack Obama had “directed every member of his national security team to pick up the pace and move forward with ideas for degrading and defeating Daesh [Isis] more rapidly, more completely, and permanently.” In Whitehall, British officials say that sense of urgency is fully shared.  Related: Peshmerga forces enter Sinjar in fight against Isis  Isis can still strike painful blows. Thursday’s bombing of the southern Beirut suburb of Bourj al-Barajneh, killing 43 people, was not only an attack on Hezbollah, the Lebanese Shia militia that is fighting alongside Assad. It was also hateful sectarianism borne of the unresolved conflict in Syria and promoted by the proxy war between Iran and Saudi Arabia, which respectively support and oppose Assad. On Friday Isis announced that one of its members had blown himself up and killed 18 others at the funeral of a pro-government Shia fighter in Baghdad.  The downing of a Russian passenger plane flying from Sharm el-Sheikh to St Petersburg, now widely seen as a terrorist act, looks like another frightening sign of the reach of Isis – whether it turns out to have been the work of the organisation itself or a local affiliate in Sinai with a more narrowly Egypt-focused agenda. It is reasonable to assume that it may have been a response to Vladimir Putin’s intervention in Syria.  It is hard at first glance to work out how these different strands come together. But in the immediate background is the renewed international drive to break the impasse in Syria, with representatives of more than 20 countries scheduled to meet in Vienna on Saturday – the second session of the widest forum yet convened to tackle the 21st century’s worst crisis and biggest humanitarian disaster.  Syrians have not been invited to take part. The assumption is that there is no way they can agree, though they might be influenced, or eventually dictated to, by a more determined effort by powerful outsiders. Prospects for swift or meaningful progress, however, look extremely slim given the apparently unbridgeable gap over Assad’s future.  Related: Mohammed Emwazi: who were his victims?  “Underlying all this is the fact that Isis is a symptom of political failings in Iraq and Syria,” said a European diplomat. “They have played on grievances so there has to be an effort to tackle the root causes or they won’t be defeated. And it is important to recognise that this is a long campaign. There is no quick way to do this. There is a real need for strategic patience.”  Kerry dismissed the now familiar criticism that the US is more interested in defeating Isis than in helping Syrians overthrow their president. US diplomatic and military actions were “mutually reinforcing,” he argued. “The more progress we make on [replacing Assad with a transitional government], the more likely we are to succeed” in defeating Isis and preventing further instability in the Middle East.  “The US needs to show that it has strategy that is working,” said Julien Barnes-Dacey, of the European Council on Foreign Relations. “Given that they will not be able to squeeze a lot out of Vienna they badly need perceived impact elsewhere.”
Islamic State fighter’s apparent death in Syria is psychological boost in a long hard war, but the capture of Sinjar from Isis in Iraq may be more significant