Belgium has struggled to develop a robust counter-terrorism strategy equal to the nature of the threat it is facing. It won’t even permit police entries into homes after 9pm, when plotters are likeliest to congregate. But Belgium’s ambassador to Australia, Jean-Luc Bodson, rejects Malcolm Turnbull’s comments this week linking Tuesday’s attacks in Brussels, and the killing of at least 31 people, with Europe’s refugee crisis.

Since the attacks on Brussels airport and Maelbeek metro station the Prime Minister has highlighted strong border security as critical to our counter-terrorism arrangements and contrasted this approach with Europe’s porous borders. He has said that Syrian refugee flows are being exploited by Islamic State to deploy terrorists into Europe.

Bodson has denied this and says it is dangerous to make a link between terrorism and refugees. While at one level the ambassador’s comments are understandable, we would argue Turnbull’s judgment is sound.

It may have been the case that until fairly recently there hasn’t been an overriding need for Islamic State to export fighters to Europe. Indeed, it imported them from Europe. But now the number of foreign fighters is plateauing and Islamic State is using refugee flows to screen the movement of some of its members into Europe.

Nearly five million Syrians have been displaced since the conflict began. About 900,000 have applied for asylum in Europe. Since declaring a caliphate from Mosul in northern Iraq in July 2014 and taking Ramadi and Palmyra in Syria in June last year, Islamic State leader Abu Bakr al-Baghdadi and his forces have suffered losses of an estimated 40 per cent of their territory in Iraq and 22 per cent of their resource base in the Middle East. Ramadi was regained in December; the assault to retake Palmyra is under way and we expect a similar advance on Mosul in due course.

This has affected Islamic State’s recruitment activity. Moving its members to Europe assists in planning attacks there. It shifts attention away from the losses in Syria and demonstrates Islamic State’s ongoing worth for recruits, financers and other supporters.

US Director of National Intelligence James Clapper recently warned that Islamic State was taking advantage of the torrent of migrants to “insert operatives into that flow” to target Western countries. A report this month from the US House Committee on Homeland Security points out that operatives have travelled out of the confict zone undetected by posing as Syrian refugees or using fake passports to launch attacks in Berlin; conduct a suicide attack against German tourists in Istanbul; develop a plot to bomb the US consulate in Turkey; carry out attacks in France; and evade authorities after a terrorist attack in Tunisia, among other incidents.

Lax counter-terrorism screening throughout Europe will continue to make these tactics attractive to Islamic State.

Using refugee streams for this purpose isn’t new. In Australia we’ve had the recent experience of a small number of people assessed to be members of terrorist groups such as the Taliban and the Liberation Tigers of Tamil Eelam using the asylum flow to move people into this country.

But it is also true there has been no shortage of terrorists already in place. As we’ve seen in Brussels and Paris, deadly attacks have been committed by people living in Europe and travelling freely across the continent. There are large numbers of people in Europe in contact with Islamic State. Many are taking the decision to act in Europe. Suicide attackers Ibrahim and Khalid El Bakraoui and bomber Najim Laachraoui are from Bel¬gium. The El Bakraoui brothers were known to police as criminals but not terrorists. The Paris attackers, while of non-European heritage, were European citizens, some born in France and Belgium while others were naturalised citizens.

Australia’s three terrorist attacks in the past 18 months at Endeavour Hills police station in Melbourne, the Lindt cafe in Martin Place and Parramatta police station in Sydney were undertaken by Australians. Man Haron Monis came to Australia 18 years earlier and had become a citizen. Numan Haider and Farhad Jabar came to Australia as children with their families. Foreign fighters Jake Bilardi and Oliver Bridgeman (although disputed) are Australian-born converts to Islam, while Abdullah Elmir (known as “Ginger Jihadi”) and Khaled Sharrouf were born here. We see a similar pattern in those arrested for plotting terrorist acts and providing other support.

Only those on the extreme Right would suggest that all terrorist attacks in Europe are caused by refugees. We have seen in Europe that such rhetoric has the potential to tear apart communities; oversimplifying the issue serves only to exacerbate the problem and risks taking away the focus from other areas necessary to our strategy to counter this threat.

But the Prime Minister is correct in pointing out that Islamic State is using the refugee flow and weak border arrangements to move some of its people into Europe. This reinforces the need for Australia to maintain a strong security focus in information collection to drive investigations, as well as immigration screening and assessment.

Jacinta Carroll is head, counter-terrorism policy centre, Australian Strategic Policy Institute. Anthony Bergin is ASPI’s deputy director.

Originally published in the Weekend Australian