Not even an hour had passed after the deadly explosions hit Brussels on Tuesday morning before the case for Britain leaving the European Union (EU) began to be made. On social media, UKIP leader Nigel Farage followed up a short message of condolence by retweeting the Telegraph columnist Allison Pearson: "Brussels, de facto capital of the EU, is also the jihadist capital of Europe," Pearson said, as bodies were still being counted. "And the Remainders dare to say we're safer in the EU!". Shortly after that, UKIP's defence spokesperson Mike Hookem released a press statement blaming the EU's "lax border controls" and "Schengen free movement" for the attacks. "There are 94 returned jihadists currently living in Molenbeek, Brussels," he said. "This fact alone should alert people to the fact that open borders are putting the lives of European citizens at risk."
Politicians using moments like these for political gain is of course nothing new. It wasn't long after a Syrian passport was found at the scene of one of last November's Paris attacks that a terrorist atrocity became a debate about refugees and migrants. The response to Hookem, Farage and Pearson was swift and indignant – even David Cameron said "today is a day for sympathy and condolence". But as the UK closes in on this summer's referendum, the likelihood of Brussels becoming a political football for proponents – and indeed opponents – of Brexit seems inevitable.
Even before the Brussels attacks, the EU's "open borders" were being linked with an increased threat of terrorism by some of the Leave campaign's big beasts. Shortly after Paris, Nigel Farage said he "couldn't think of a better reason for Britain divorcing itself from the European Union" and a few months later, Iain Duncan Smith – whose recent resignation from the Department for Work and Pensions has been tied to his Brexit advocacy – made a similar point to the BBC: "This open border does not allow us to check and control people that may come," he said. The website of the Vote Leave Campaign – a cross-party group involving UKIP, the Conservatives and Labour – also says EU membership makes it "much harder" for Britain "to fight terrorism and deal with criminals".
With current polls so narrow – a recent survey run by NatCen Social Research showed Remain on 51 percent and Leave on 49 percent – you can expect the Leave campaign to ratchet this up a few notches post-Brussels. Hooken's reference to the number of returned jihadists in Molenbeek, the Brussel's neighbourhood described as a "jihadist breeding ground" was clearly an attempt to tap into the fear that Europe's so-called "leaky" internal and external borders means nothing is stopping them from coming over here. Future attempts might not be quite so crass and opportunistic as this occasion, but they are unlikely to go away in the lead up the vote on the 23rd June.
One of the reasons this is so attractive for Leave campaigners is that voters – particularly those leaning towards Brexit – are heavily influenced by immigration, and by extension, terrorism and security. A recent poll commissioned by the Observer found that immigration is by far the leading factor influencing people. The same poll also found that 38 percent of people surveyed had changed their minds over which way they would vote in the past six months, including 22 percent who said they were now more likely to vote for Brexit. Perhaps this is because your average person is confused and undecided. But it was also a time period, as the newspaper makes clear, that included "the Paris terror attacks, the worsening refugee crisis and the mass sexual assaults in Cologne on New Year's Eve", a strong indication of the impact Brussels might have.
Of course you can also expect this narrative to be robustly challenged by those advocating for Remain. How the atrocity yesterday morning was allowed to happen remains unclear, but none of the reasons cited so far appear to involve Europe's internal or external borders. Two of the suspected perpetrators – Khalid and Brahmin El Bakraoui – were radicalised Europeans known to the police and tied to the Paris attacker Salah Abdeslam, who was captured in Molenbeek last Friday. And with more fighters having left Belgium to join the conflict in Syria per head than anywhere else in western Europe, the country's decentralised, fragmented public services and under-funded intelligence agencies that don't speak to one another have all been raised as problems. "We just don't have the people to watch anything else and, frankly, we don't have the infrastructure to properly investigate or monitor hundreds of individuals suspected of terror links" one counterterrorism official told Buzzfeed News yesterday.
Remain campaigners are also likely point out the importance of cross-border intelligence cooperation with European agencies like Europol and other systems like the European Arrest Warrant and the Schengen Information System, which the UK joined last year after the Charlie Hebdo massacre.
Unlike most of the EU's 28 states, the UK is not a member of the Schengen Zone, a passport-free area that established freedom of movement within the EU's internal borders. That makes the possibility of jihadis entering Britain after crossing into Europe – something the head of Europol Robert Wainwright has anyway dismissed as a systematic problem – extremely unlikely. For EU citizens it's obviously different, but independent border controls mean people entering Britain still have their travel documents checked. While the risk of a major attack is high, the real threat tends to come from home-grown extremists, rather than foreign nationals from Europe or elsewhere.
Whether any of this will mitigate the temptation to pull up the drawbridge remains to be seen. Perhaps the public will see through the dog-whistling or perhaps the Remain campaign will double-down on its own version of "Project Fear" – a mixture of economic doom-mongering and the horrifying prospect of Spanish expats fleeing Malaga. The swift fall of the pound on currency markets yesterday morning and the shortening of odds for Brexit offer smalls clues about how it might pan out. But don't trust the markets, bookies, polls or pundits. You'll have to wait til the 23rd to find out.
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