Ukraine crisis: Mariupol asks, are we next?

The soils of eastern Ukraine are deep and rich. For centuries this has been the breadbasket of eastern Europe.

Deep soils also make for easy digging, and on the hills east of Mariupol there is a lot of digging going on.

It is a scene reminiscent of the western front in 1914.

Soldiers with grizzled faces and shaggy beards stand shoulder deep in freshly dug slit trenches.

Their ancient weapons point to the east, towards Russia, towards the enemy.

The enemy is now close. At the bottom the hill lies the small village of Shyrokyne.

Ten days ago it was still in government hands. Not any more.

There is supposed to be a ceasefire in place, but Commander Sobol is nervous.

Our vehicles stand out on the bare hill-top. "Poyekhali! Poyekhali!" he shouts. "Lets go! Lets go!"

Reluctantly we trudge back to our cars. As our convoy rumbles back down the muddy track there is a large bang behind us.

A grey cloud of smoke drifts upwards. The commander was right to be nervous.

Everyone expects an attack here. It may come in days, but more likely it will be weeks.

Mariupol is the last major city in eastern Ukraine still under government control.

Commander Sobol tells me his men are outmanned and outgunned: "We need better communications and surveillance, drones.

"We need more modern anti-tank weapons because [the rebels] have Russian T-90 tanks which are much better than ours. We need sniper rifles, and we need vehicles, like your British Land Rovers, they would be excellent."

On the eastern outskirts of Mariupol in a Soviet-era community centre 66-year-old Stepan and 74-year-old Vera are sitting on a bed. Until two weeks ago they were neighbours in Shyrokyne.

Then the shelling began.

"They were firing every 10 minutes," Vera says. "Shrapnel was coming through the windows. On the 14th the shelling got heavier, so we had to go."

"I was always sure that Russia would invade," says Stepan, who has a huge walrus moustache and big sad eyes. "Right after we got independence in 1991 the Russians put a tank brigade on the border near here.

"If you stockpile weapons it means one day you intend to use them. Why should you deploy arms against your brothers and friends?"

Vera is far less philosophical. Her eyes are imploring and she is close to tears as she describes what has happened to her.

"We never thought this could happen to us" she says.

"We saw the fighting in Donetsk and we thought thank god it is not happening here. But now look at us! We used to lead happy peaceful lives, now we don't have any life at all."

The question now is whether the rebels are ready to push into Mariupol itself. Perhaps even more important, are their backers in Moscow prepared to take the risk?

Attacking a city of half a million is not simple. It would bring a high cost in lives and a much harsher response from Europe.

It could tip the US in to the full scale arming of the Ukrainian military.

The city might also fight. Mariupol is home to a right-wing paramilitary militia known as the "Azov Battalion".

It was formed in the aftermath of the uprising last year to defend Ukraine's sovereignty.

Its members are well-equipped and highly motivated and have sworn to defend the Mariupol with their lives.

At the same time perhaps half of the city's population is sympathetic to pro-Russian rebels.

In a neighbourhood of drab grey concrete apartment blocks on the eastern edge of Mariupol a group of burned out cars lie abandoned in a parking lot.

They were destroyed in a rebel rocket attack at the end of January.

Thirty people were killed when the grad rockets came raining down in the middle of the day.

As I inspect the bomb damage Victor Vladimirovich, a man with a large fur hat and piercing blue eyes, stops to talk.

"The rebels did not do this," he says, without irony. "They would not do this to us. They are our people. How is it possible they would fire on their own people?"

Back in the refugee centre Stepan is putting on his coat, he wants to get out for a walk. He shrugs when asked how all this will end.

"I don't know, I really don't know," he says. "In 1942 the Nazis came here and burned down our house.

"In 1944 the so-called Russian liberators came and they shot my father. Now it has all started again.

"We are always stuck in the middle."