As NATO’s leaders meet this week for the summit in south Wales, the lofty atmosphere will be freighted with awareness both of the continuing ‘ethnic cleansing’ and horrific executions being perpetrated by Islamist militants loyal to Islamic State (IS) in Syria and Iraq.

With news that extremists now control much of the area that borders Turkey and surrounds the Syrian city of Raqqa, the alliance’s leaders should not allow their discussions to be fully hijacked by the crisis in Ukraine.

However, in its focus on events in Eastern Europe, NATO itself, and much of the analysis surrounding this summit, appear to be downplaying the gravity of the extremist threat.

A direct attack on NATO-member Turkey by militants would trigger Article 5 of the North Atlantic Treaty, by which ‘an armed attack against one or more [of the signatories] shall be considered an attack against them all’.

It is arguable that Turkey’s sovereignty has already been attacked given that militants currently ‘hold 49 hostages seized from the Turkish consulate in the Iraqi city of Mosul in June, including the consul general, special forces’ soldiers, diplomats and children’.

Meanwhile, outgoing NATO Secretary-General Anders Fogh Rasmussen pledged that NATO would ‘take all steps necessary’ to defend Turkey if it was attacked.

Despite this, Turkey appears decidedly ambivalent over the best approach to take towards the extremists – a problem revealed by its reluctance to arm Kurdish Peshmerga fighters and exacerbated by its fragile relations with Russia.

In contrast to Ukraine, Turkey is already a NATO member. Instead of agreeing to Ukrainian requests for the accession to the alliance, an action that would be both unnecessarily provocative and over-extend NATO’s purview, the alliance should decisively deal with the Gordian-knot of uncertainty embodied by Ankara.

NATO must take steps to ensure Turkey’s wholehearted commitment to the alliance – with a range of inducements and requirements.

As a recent article for the journal International Affairs points out, the purchase by the government of Recep Erdoğan in September 2013 of a Chinese missile defence system points to his increased frustration towards NATO.

The country’s steadfast commitment to NATO (it joined in 1952) should be recognised with enhanced support – it has been limited thus far to the deployment in January 2012 of six air defence batteries under NATO command.

Meanwhile, although Turkey ‘ranks among the very few NATO nations that have a high defense-spending-to-GDP ratio’, it must also be pushed (along with other European members such as Germany) to increase its defence spending commitment.

Secondly, the NATO ally should be granted conditional access to the European Defence Agency, an EU body of which another non-EU member, Norway, currently has opt-in status.

However, there is no way in which the so-called ‘Islamic State’ can be viewed by Turkey as a viable neighbour or trading partner.

Indeed, just like the European Union, with whom Turkey has been conducting membership negotiations, NATO must have a zero tolerance attitude towards countries that try to play it both ways with regards to enemies of fellow alliance members.

Assistance must be conditional on the government strengthening its crackdown on militants traveling through its territory and on the strengthening of rule of law and human rights provisions.

Failure to comply should be met by sanctions by the time of the next NATO summit, leading ultimately to the possible ejection of Turkey as an alliance member.

While embodying a certain amount of risk, this would ensure NATO both lives up to its purported ideals and can follow through on its strategic commitments.

Related to this, it is imperative that NATO makes clear its renewed commitment to the founding principles of the 65-year-old alliance: these are, as stated in the preamble to the 1949 treaty, ‘democracy, individual liberty and the rule of law’.

Through increased support and more decisive and demanding leadership, NATO must ensure that Turkey reinforces its wholehearted commitment both to the alliance’s values and to the cause of eradicating extremism.