Mr Drummond said: “I think any strikes will be restricted to the border regions because strikes deep into Russia would be a big escalation.
“Ukraine will want to conduct terrorist activity in Russia… if Russia wins in Ukraine or is given any kind of victory, I think Ukraine will conduct a counterinsurgency campaign inside Russia, and that would be much more devastating than anything we have seen on the frontlines.
“It will be really unpleasant.
“The terrorist activity would include bombing schools, bombing infrastructure… that would begin in earnest if any peace deal was imposed on Zelensky.
“They are absolutely planning these kinds of attacks now. No question. I think this is more terrifying for Putin than a conventional war, because if Ukrainians unleash this terror campaign in Russia, he will lose power very quickly because people will say ‘you are not doing enough to stop it.”
Ukraine’s ability to strike back against Russia has been bolstered after the US permitted Kyiv’s troops to hit Russian territory with American weapons.
On Friday, Ukraine began doing just that.
Ukraine’s general staff announced: “The Defence Forces of Ukraine attacked the Kerch ferry crossing with ATACMS [US Army Tactical] missiles, which was actively used by the enemy to secure its grouping of troops in temporarily occupied Crimea.”
The Kerch Ferry crossing separates Crimea from the Russian region of Krasnodar Krai.
Ukraine claimed to have “significantly damaged two ferries carrying railway and car transports.”
