BRUSSELS A year after Islamic State suicide bombers killed 32 people in Brussels, Belgian authorities say much remains unclear about who ordered the attacks, even if those who staged them are either dead or in jail.
The March 22 bloodshed in Brussels hit Zaventem airport and a metro train, four months after bombings and shootings in Paris that killed 130 people. Both sets of attacks were carried out by related cells of young Muslims, some of whom had returned from fighting in Syria.
Since then, Belgium has remained on high alert as it tries to curtail threats both at home and from militants who may return from the Middle East.
“We will only have certainty when the situation in Syria and Iraq is resolved,” one senior official said of the inquiries into the Brussels attacks. Those two countries have attracted over 400 Belgians to join the ranks of Islamist militants, according to a study by the…