have destroyed military equipment, frightened beach goers,

and prompted thousands of residents to evacuate to Russia.

After more than eight years under Moscow's control,

scenes of war have returned to Crimea.

(speaking foreign language)

- [Reporter] For several recent incidents,

Ukraine hasn't claimed responsibility,

but Russia's operations have been seriously disrupted

as Ukraine increasingly focuses on striking facilities

and supplies behind Russian lines.

- Actually, what they're doing is part of a broader strategy

which is to try to squeeze the Russians

out of the south of the country.

- [Reporter] So as the war enters a new phase

and President Zelensky vows to take back the territory

at the heart of Russia's operations,

here's why Crimea has emerged as an important battleground.

Russia's military seized Crimea,

which is internationally recognized as Ukrainian territory,

in 2014.

Since then, Moscow has built military bases

and weapons stores on the peninsula.

(speaking foreign language)

- [Reporter] When Russia invaded Ukraine in late February,

those hubs became important locations

from where Moscow could deploy forces and top up supplies.

- In the early days of the war, Crimea was used

as a jump off point for Russia's military.

- [Reporter] Russia's initial strategy

was a multi-directional invasion

with the goal of capture and keep, but after that failed,

fighting shifted to Eastern and Southern Ukraine.

- Since then, it's Crimea that's been kind of a rear base

for Russian armed forces who are occupying

the south of Ukraine.

Ukraine is now attempting to push those forces out.

(explosion booming)

- [Reporter] Since taking control of parts

of Eastern Ukraine in July,

Russia's forces have appeared to slow down

and Ukraine has repeatedly hit occupied areas

with targeted strikes on key infrastructure

that was being used by the invaders.

- Ukraine, it thinks it can't take the Russians on

in a tank battle.

So they're being clever about it.

Their aim is to degrade the Russians.

The Ukrainian official said to me,

it's like 1,000 stings from a bee

in order to disable Russian capabilities,

their ability to wage war and demoralize them

and force them to withdraw.

- [Reporter] Crimea is now key to that strategy.

A blast at a Russian airbase on August 9th

destroyed several war planes,

according to Western intelligence officials.

And as seen in these satellite images

that contradicted Moscow's claim

that no war planes were lost.

Russia blamed an ammunition explosion,

and Ukraine didn't take responsibility for the damage.

But the blast had consequences.

Russia relocated some planes and aircraft to its mainland,

according to Ukrainian military intelligence.

A week after the airbase was hit,

explosions at an ammunition depot damaged rail tracks

and power lines, complicating Russia's efforts

to transport ammunition and other supplies.

Ukrainian officials said the attack was indeed Ukrainian,

and Russian officials blamed saboteurs

in their first official acknowledgement

of a major attack on the peninsula.

Still, that doesn't necessarily mean Ukraine

is about to retake Crimea.

- Certainly Crimea eventually is a target,

but the Ukrainians are going about it very methodically,

piece by piece.

- [Reporter] Russian diplomats didn't respond to a request

for comment about the effects of what's happening in Crimea

on Moscow's campaign.

But as a new phase starts in the conflict,

the peninsula is at the center of Ukraine's efforts

to show that it can damage Russia's army

where it didn't expect it.