Cities are responding to the targeting of crowds by terrorists in vehicles.
We live in dangerous times, but how we react to the risk of terrorism will have impacts on our public realm for many years.
A memorial on Las Ramblas following the attack.
A toxic combination of history and social tension makes Spain fertile ground for extremist recruitment.
La Rambla runs right through the centre of Barcelona.
The boulevard runs through the heart of the city, drives its tourist economy and acts as a symbol of life in Catalonia.
Spain plays a relatively inconsequential role in the fight against Islamic State.
The location and targeting of Islamic State's latest attack, on the Spanish city of Barcelona, deviates from the group's previous efforts.
At least 16 people have died, and scores more have been injured, in a terror attack on Barcelona’s Las Ramblas strip.
Barcelona 2017, London 2017, Berlin 2016, Nice 2016. In all of these cases the weapon of choice was a vehicle, driven at speed, into crowds innocently going about their daily business. Barcelona is just…
Did Trump’s rhetoric played a part in radicalizing the far-right protesters in Charlottesville?
AP Photo/Steve Helber
Trump is a master of using anger to motivate his base. An anti-terrorism researcher explains how to stem the tide.
Illicit firearms and small weapons recovered during security operations being destroyed in Nairobi.
German Chancellor Angela Merkel’s comments about weapons as part of development for Africa could have the opposite effect if conditions aren’t strict and democratic processes aren't followed.
Citizen militia march in Charlotttesville, August 12.
EPA/Virginia State Police
Having stoked white resentment for his own benefit throughout his campaign, Trump is still emboldening it.
Leader of Fulani herdsmen Haruna Usman pictured by Reuters in 2014.
Attacks by Fulani herdsmen on communities in West Africa are increasing in number and in sophistication. Regional and national authorities must respond promptly to arrest the threat.
Fortress Europe: Macdeonian soldiers patrol the Greek border.
New research questions the scale of support for tougher border security across Europe.
Police raided several Sydney properties over the weekend in relation to possible terror plots.
The government seems hell-bent on pre-crime arrest, prosecution, and punishment for terror offenders – while falling short in providing the necessary long-term support.
Local vigilantes patrol communities in north east Nigeria to repel attacks by Boko Haram militants.
Nigeria's failure to protect its citizens from Boko Haram's insurgency has given rise to vigilante groups north east of the country.
Peter Dutton (right) is set to assume responsibility for the newly created home affairs portfolio.
The move to consolidate security agencies under one minister upends generations of conventions on how security intelligence and executive police powers are managed separately.
The martyrdom of the Maccabees by Antonio Ciseri.
The violent evolution of martyrdom.
Malcolm Turnbull announced the proposed changes in front of heavily armed special forces soldiers.
The effectiveness of the changes to the ADF's role in counter-terrorism operations will depend heavily on the willingness of state police to accept military advice and assistance.
Terrorism has resulted in higher security surcharges at ports and airports.
The effects of terrorism in one country spill over across national borders to reduce the trade of other nations. This reduction in trade is long lived and may make it harder to combat terrorism.
Iraqis celebrate the recapture of Mosul from Islamic State.
While Islamic State might be taking significant blows, including the recapture of the key Iraqi city, there is no reason to expect the violent and radical group will disappear.
Abu Bakr al-Baghdadi, painted portrait.
After a major defeat in Mosul, Islamic State seems to have suffered a blow that could end its goal of establishing a cross-border caliphate in the Middle East.
Sheen Ibrahim, Kurdish fighter from the People’s Protection Units (YPG), walks together with other YPG fighters in Raqqa, Syria, June 16, 2017.
The US is doing so with increasing frequency around the world – most recently with Kurdish fighters in Syria. A scholar explains what can go wrong, and why this approach is likely to continue.
Iranians watch a soccer match between Iran and Uzbekistan at a Tehran cafe last month. Compared to their neighbours, Iranians are not plagued by ethnic tensions.
AP Photo/Ebrahim Noroozi
Unlike its neighbours, Iran's different ethnic groups live in relative peace and harmony. Given terrorism is often spurred by ethnic conflict, will Iranians be spared further terrorist attacks?