US President Barack Obama this week will explain to Americans (and any allies thinking about buying into an international coalition) his plan to go on the offensive against Islamic State, which has captured vast amounts of territory in northern Iraq and Syria, and which Obama says can become a threat to the United States.

He’ll meet with congressional leaders on Tuesday to seek their support.  And then on Wednesday, President Obama will make a speech “describe what our game plan's going to be”.  The speech will take place a day ahead of the anniversary of the 9/11 attacks.

“I just want the American people to understand the nature of the threat and how we're going to deal with it and to have confidence that we'll be able to deal with it,” Mr. Obama said in a televised interview.  “The next phase is now to start going on some offense,” he said.

The US has already conducted weeks of air strikes on Islamic State targets in Iraq, the latest of which supported Iraqi security forces protecting the Haditha dam – a major source of energy in Iraq.  The Pentagon says all US aircraft left the area safely, immediately after destroying Islamic State’s armored vehicles, some carrying anti-aircraft artillery.