The remarkable advance of the terror group Islamist State in Iraq and the Levant (Isis) though north-eastern Iraq over the past two weeks has sparked Israeli fears over instability in neighbouring Jordan and the prospect of closer ties between the West and Iran.
As Isis forces and allied Sunni militias completed their takeover of Iraq's second-largest city, Mosul, over the weekend, there were reports of mass executions of Iraqi Shia soldiers and plans to continue on towards Baghdad.
Intelligence agencies estimate that cash from captured Syrian oil wells and other foreign sources have combined to make Isis arguably the wealthiest and most capable terror group in the world.
The rapid collapse of Iraqi government control over a large area has elicited an often muddled response from the Obama administration. This was the same administration that, before completing the American withdrawal from Iraq in December 2011, invested an estimated $25 billion in building up a new Iraqi army.
While senior State Department officials said that there had been some discussion with Iranian representatives over the situation in Iraq, the Pentagon categorically denied that there would be any military co-ordination with Iran.
Iraq does not border Israel but events there could have a profound effect on Jordan, which serves as a buffer-region between the two countries. Since the fall of Saddam Hussein's regime in 2003, Israel has felt relatively secure about its "eastern front".
The Hashemite Kingdom has also weathered the Arab revolutions relatively well. But an emergence of a heavily-armed, anti-Western jihadi entity on its eastern border could destabilise the kingdom, already under economic pressure due to the million Syrian refugees in its territory.
Senior Israeli representatives who participated in high-level meetings with the Jordanian leadership in recent days acknowledged there is a deep concern in Amman over the Iraqi situation.
The "thawing" in Iran's relations with the West, as seen this week in Foreign Secretary William Hague's announcement that the UK would reopen its embassy in Tehran, is a worry for Jerusalem. But Israeli experts are sceptical that any significant alliance between the US and Iran will emerge over Iraq as there are still many sources of tension between the sides, not the least the P5+1 talks over Iran's nuclear programme.
Developments in Iraq have also shifted attention away from the previous concern regarding Isis: that hundreds of European jihadis fighting with the organisation in Syria may continue their jihad in their home countries. At this point, it still far from clear that Mehdi Nemmouche, the suspect alleged to have shot four people last month at the Jewish Museum in Brussels, was operating alone.
Nemmouche spent a year with Isis in Syria. Some analysts believe, therefore, that the shooting was connected in some way to the organisation and may be only the first of a series of such attacks. But this imminent threat to civilians in Europe has been eclipsed, for now, by the prospect of Iraq's collapse and dismemberment.