In an emotional address via a video link to a joint session of the US Congress Ukraine’s president Volodymyr Zelensky appealed to the lawmakers to help his country fight Russia. He asked for two things: the enforcement of a no-fly zone and supplies of more weapons.

Christopher Michael Faulkner and Andrew Stigler describe how no-fly zones work, and where they have and haven’t been successful. They underscore that the risks are enormous when the enemy is a nuclear power - too high even for the most ardent of Ukraine’s supporters.

What about the request for more weapons? Vincent E. Castillo explains how US weapons and equipment make their way from storage at US bases in NATO countries all the way into soldiers’ hands on the front lines of the war. It’s a path that includes many opportunities for failure, including Russian attacks on transport convoys.

Caroline Southey

Founding Editor

Ukraine wants a no-fly zone. What does this mean, and would one make any sense in this war?

Christopher Michael Faulkner, US Naval War College; Andrew Stigler, US Naval War College

Ukraine’s President Volodymyr Zelenskyy has asked the US to impose a no-fly zone over Ukraine. Doing so in this kind of international conflict would be unprecedented and might not make sense.

How weapons get to Ukraine and what’s needed to protect vulnerable supply chains

Vincent E. Castillo, The Ohio State University

The Russian invasion of Ukraine has triggered an unprecedented outpouring of humanitarian and military aid. Protecting those supply chains is essential for delivering materiel to the frontlines.

Kyiv has faced adversity before – and a stronger Ukrainian identity grew in response

Matthew Pauly, Michigan State University

A historian looks back at a time when Ukrainians battled for control of the capital, but succumbed to a superior Soviet army.

Russia’s invasion of Ukraine is illegal under international law: suggesting it’s not is dangerous

Cathleen Powell, University of Cape Town

No state in the global community should have to earn Russia’s compliance with the law. If the rule of law is not respected, the entire global community becomes as vulnerable as Ukraine is now.

Putin’s Russia: how the ex-KGB strongman has gradually turned the clock back to Soviet repression

Stephen Hall, University of Bath

The death of ‘glasnost’ and the return to the oppression of Soviet Russia.

Algeria and Libya are unlikely to plug Europe’s energy gap

Inga Kristina Trauthig, King's College London; Amine Ghoulidi, King's College London

Maghreb countries are unlikely to step up to replace Russian gas supplies without an implicit nod from Moscow.

Why the Uttar Pradesh election result is important for Narendra Modi’s plans

Subir Sinha, SOAS, University of London

India’s prime minister has unexpectedly won a big state election, further boosting his power.

Benefits of statins may have been overstated – new study

Paula Byrne, RCSI University of Medicine and Health Sciences

New review suggests many don’t benefit massively from taking a daily statin.

The Ebola virus can ‘hide out’ in the brain after treatment and cause recurrent infections

Kevin Zeng, U.S. Army Medical Research Institute of Infectious Diseases

Although treatments for Ebola have helped many people overcome this deadly disease, the virus can persist in the brain and cause a lethal relapse.

Grunts, boops, chatters and squeals — fish are noisy creatures

Audrey Looby, University of Florida; Amalis Riera, University of Victoria; Kieran Cox, University of Victoria; Sarah Vela, Dalhousie University

Growing research shows that fish produce sounds that other creatures listen to to find food and avoid becoming prey. A new database compiles research on these fish sounds.

ICC case against Kenyan lawyer Gicheru: it matters, but not for victims of the violence

Kerstin Bree Carlson, Roskilde University

For the ICC, the case against Paul Gicheru represents the possibility for the court to clock a win where so far it has only suffered losses.