Nearly 1,000 people were injured or killed in terrorist attacks involving refugees over a four-year span, with Germany facing the highest number of terror plots, according to a new Heritage Foundation report published Monday.

Data collected from the 194 terrorist plots detected across Europe between January 2014 and December 2017 point to a more than one-in-three chance that Germany will be the country targeted in future terror schemes, with civilians being the primary bullseye.

Though only 32, or 16 percent, of those terrorist plots involved refugees or asylum seekers, 41 percent of all plots occurred in Germany. France was the second most targeted country, with Belgium and the United Kingdom trailing closely behind.

The report comes as German Chancellor Angela Merkel faces the threat of her government collapsing over its open-door policy toward migrants, which critics say has left the country more vulnerable to terrorism. Germany is still struggling to absorb the 1.4 million asylum seekers who arrived three years ago primarily from Syria, Afghanistan, and Iraq.

"It's not as if the Islamist terrorism threat appeared with the Germany refugee flow, of course there were plots there in the past, but the scale has transformed entirely since [Merkel's] decision to open the borders," said Robin Simcox, a terrorism and national security analyst at the Heritage Foundation who authored the study.

"The amount of plots that Germany faced after the 2015 refugee flow just increased exponentially, and when you look at the perpetrators behind those plots it's more often than not they're recent arrivals into the country and there's very often a Syria component to it."

The report found that of the 15 Syrian jihadists who plotted attacks over the past four years, 12 were involved in operations targeting Germany.

Simcox said Europe must take immediate steps to more quickly deport migrants who have been denied asylum, particularly given that nearly three-quarters of attackers were asylum seekers who either either committed an attack or had it thwarted within two years of arrival.

This issue became clear in Germany in December 2016 after police missed multiple opportunities to arrest Anis Amri before he drove a truck through a Christmas market in Berlin, killing 12 people. The Tunisian national, who pledged allegiance to the Islamic State, was awaiting deportation when he carried out the attack. Amri remained in Germany because he did not have a valid passport.

"Ultimately, the general public in Europe is very concerned about this issue. Proof of that is pretty obvious in elections that have taken place in recent years—in Austria, Germany, Italy—where immigration has proven to be such an important topic," Simcox said. "I don't see how the mainstream politicians in Europe can really begin to earn the trust of the voters whose trust they've lost in recent years. They got this badly wrong; they misjudged this entirely, the scale of the problem and their ability to cope with it, as well as its impact on national security."