Q. How does the tank deal work?
. Germany has agreed to send its own Leopard 2 tanks and grant export licences to its allies so they can also send theirs.
The German-made vehicles will form roughly two battalions of about 40-50 tanks each.
The Leopards will be joined by Challenger 2 tanks from Britain and Abram tanks from the US.
Q. How long will it take to send them?
A. There is no concrete timetable in place for getting Nato-standard tanks on to the battlefield in Ukraine. There are still questions over how many of the tanks promised to Kyiv are combat-ready.
There is also the issue of training Ukrainian crews to operate the heavy armour. Most of Kyiv’s western backers hope the tanks will be in operation before Russia has the opportunity to launch any new offensives.
The US-made Abrams will take longer. The promised 30-50 tanks will not be from existing stocks but will probably be newly built, meaning they may not arrive for over a year.
Q. Will they make a difference?
A. Nato experts believe that with enough tanks, Ukraine would be able to push into Russian-held areas previously unreachable with the equipment its soldiers once had.
With the conflict at a stalemate, military experts believe Russia and Ukraine are planning fresh offensives in the spring, when the mud dries. Without tanks, Ukraine has often been unable to break through Russian defensive lines.
Combining heavy artillery, heavy armour and lighter infantry fighting vehicles in combined operations, as practised by western armies, would give Ukraine a new edge.
Q. What comes next after the tanks?
A. The west has been careful not to give offensive weapons to Kyiv for fear of provoking Vladimir Putin. But as Ukraine’s chances of winning have increased, the west could consider sending longer-range missiles and fighter jets.
Telegraph Media Group Limited