The UK and its allies now face many conflicts on several fronts:

in Syria, a hostage from Scotland faces the threat of being murdered; in Glasgow, the family of a young woman who joined terrorists in Syria have appealed to her to come home and warned that what happened to them could happen to others; and in Ukraine, an on-off ceasefire with rebels, supported by Syria's ally Russia, has raised the prospect of a new cold war.

Together, these crises, complex and inter-connected, present a considerable threat to the security of the UK, the US and their allies, and yesterday President Obama and the Prime Minister David Cameron were firm in their responses.

Ahead of the Nato summit, the President said he would not be intimidated; at Prime Minister's Questions yesterday, Mr Cameron said the UK would not waver in the aim of defeating terrorism. Mr Obama also said the US strategy was to ensure that Islamic State (IS) was not an ongoing threat in the region, but that any potential solutions would take time and effort.

The problem for the US and the UK is that any potential solutions are overshadowed and constrained by the legacy of the wars in Afghanistan and Iraq. The failure of those wars means the US will not countenance the idea of sending ground troops into the region (at least while Mr Obama is president and probably for a long time afterwards).

That is understandable - the last thing the region needs is another US administration rushing into war without thinking it through - but it also means the options for pushing back the IS extremists, helping any hostages, and bringing greater stability to the region are limited.

The US has had some success with airstrikes, which have succeeded in disrupting some IS activities, but airstrikes alone will not deal with the problem of a network of terrorists on the ground using the weapons of kidnapping and radicalisation. So if troops on the ground are out of the question, what other options are available?

One option could be supporting moderate rebel fighters in Syria, although that is controversial and the difficulties of being sure who the UK would be arming makes it a far from perfect option.

Another option would be opening the kind of dialogue with the regimes of Iran and Syria that would have been out of the question just a few weeks ago. Any action in Iraq should also be in consultation with the government of the country and it must have what it lacked the last time: clear military and strategic objectives.

Whatever the way forward, Russia will have an important role to play because of its considerable influence with President Assad and the Syrian regime. As for the role of the US and the UK, there will be many who believe they are in no position to stabilise the most troubled parts of the world when they have already made such a mess of Iraq and Afghanistan, but inaction is not an option. Both countries must engage with everyone they can, friend and former foe, to tackle the threat.