Al Jazeera: If pro-Russian forces try to claim territory beyond Donetsk and Luhansk, what kind of welcome would they receive?

Khara: They will meet up to 260,000-strong armed forces and territorial defence.

We have some 400,000 veterans who went through the war in Donbas – they have combat experience and certainly will not have mercy towards the invaders. I’m not talking about the civilians.

It’s going to be a bloody hell for the Russians. See, if they decide to cross [the border] and especially if they then decide to enter our cities… Thanks to the British, we have pretty powerful anti-tank missiles that can be used in urban warfare, and certainly, we have enough of our own to deploy.

Even if you look at Russian-speaking cities like Kharkiv or Odesa, people are not going to convert their flourishing cities into what Russia has been doing with Donetsk and Luhansk for eight years.

Russia should have no illusions that Russian-speakers or ethnic Russians are going to welcome them on our territory – they will be fighting. And actually, if you have a look at the language composition of those who are now in the trenches of Donbas from the Ukrainian side, the majority of them are Russian-speakers.

We have no choice. War was imposed on us, we are going to fight back, and I haven’t seen any sign of Ukrainian society being tired of war or [preparing to] capitulate to Russian demands.

Al Jazeera: Do you think there remains a possibility for a diplomatic solution?

Khara: Even though I’m a former diplomat, I believe there is no room for diplomacy with Russia at this point because, with Ukraine, Russia has twofold goals.

Firstly, to return Ukraine to its sphere of influence and limit our ability to choose our alliances and way of life. [Russia wants us to be] a sort of pro-Russian buffer zone, and that’s not going to happen.

Secondly, they’re trying to use Ukraine as a leverage against the European Union and NATO, to divide the Europeans between themselves and Europeans from the Americans.

After the Russians published [their security demands], they converted this so-called crisis into something much bigger than Ukraine.