As the Nato summit on international security opens this week in Vilnius, one obvious issue will be the success or otherwise of the Ukrainian counter-offensive. Apart from the liberation of a few villages, where are the victories earlier forecast by figures like head of military intelligence Kirill Budanov, who predicted the Ukrainian army would be in Crimea by the end of spring? Hopes of a quick push to the Azov sea, inspired by the retaking of Kharkhiv last September, have hit a sandbar this time round: denser Russian defence lines and widespread use of landmines.