Iran and the United States lurched closer towards an undeclared war yesterday when Teheran's Islamic Revolutionary Guard Corps (IRGC) launched missiles at US-Iraqi bases in Iraq - but there remains room for de-escalation.

The attack, in retaliation for the killing of IRGC commander Qassem Soleimani by the US last week, was calculated to make a statement but not cause casualties, analysts said, leaving US President Donald Trump with broader options than to simply strike back.