People mourn the victims in front of the Stock Market in downtown Brussels, Belgium, March 23, 2016. At least 34 people were killed and 180 injured after explosions at Brussels airport and a metro station on Tuesday. (Xinhua/Ye Pingfan)
Tuesday's terror attacks in Brussels have led to an embroiled debate over "Brexit", Britain's referendum on the membership of the European Union (EU).
Within an hour of the first attack, the far-right UK Independence Party (UKIP) issued a press release linking the attacks to the EU's immigration policies and the Schengen passport-free zone. This sparked an escalation in comments over the following 24 hours, mostly on social media.
In the release, UKIP defense spokesman Mike Hookem, who is also a member of the European Parliament, said: "The fact that terrorists can strike at the heart of the EU with apparent ease shows that they are perfectly placed to exploit the lax security situation created by the Schengen agreement and the EU's open door policies."
Hookem added that despite the arrest at the weekend of Salah Abdeslam, who is suspected of involvement in the Paris attacks of November last year, "these (latest) attacks should come as no surprise when you consider that the head of Europol warned that as many as 5,000 ISIS-trained jihadists are wandering free in Europe."
Hookem was referring to an interview given on Feb. 19 by Europol director Rob Wainwright to a regional German newspaper in which he said between 3,000 and 5,000 EU citizens who have been in terrorist training camps in the Middle East have slipped back into Europe.
"In Brussels alone, there are 94 returned Syrian jihadists living in the Molenbeek area," Hookem claimed. "Add to this the archaic police system in Belgium and a total lack of intelligence sharing and you have a recipe for disaster."
On Wednesday morning, UKIP leader Nigel Farage posted on his Facebook page: "Next time you hear the (UK) Prime Minister say that Britain must remain in the EU for the sake of our security, please think of Brussels."
These and other remarks from populist politicians were condemned as exploiting a human tragedy for political gain.
British Prime Minister David Cameron said it was "not appropriate" to be making a link between the Brussels attacks and immigration at such a time.
Writing on the website InFacts.org, which is campaigning for Britain to stay in the EU, its editor Hugo Dixon, pointed out that the United Kingdom is not in the Schengen area and thus does have large degree of control over its borders.
Dixon continued that while the United Kingdom is not exposed to Schengen, the country still plays a big role in designing European counter-terrorism policies.
"The Brussels and Paris attacks are a reason to stay in the EU, not quit," he wrote.
Nevertheless, the events could have big implications in the run up to the June 23 referendum on "Brexit".
Since the Paris attacks, British officials have feared that another terrorist outrage in Europe could severely damage the argument for staying in the EU, regardless of the motives behind an attack, or its perpetrators, or indeed whether EU membership is in any way relevant. When it comes to the referendum, people's perceptions will count just as much as hard facts.
Immigration has consistently been one of the top issues of concern among British voters, according to opinion polls.
And while there is no obvious link between terrorism and immigration from other EU countries, events such as Paris and Brussels could feed a sense of fear among many Britons that simply being so open to the outside world increases the risk of "importing" terrorists into the country.
On March 20, a website "What UK Thinks" issued its latest "poll of polls" averaging results from various opinion surveys. This put the "remain" and "leave" camps neck and neck, each at 50 percent, with recent months trending towards Brexit.
Both sides of the debate will be watching new polls over the coming week to see if the Brussels attacks have swayed people's views about Brexit one way or the other.
