The mother bear counterattacked, fighting to the death with the lion when it dared to kidnap her cubs.

A war broke out here. The lion decided to go hunting today and its target is the little bear.
The little bear was playing in the big meadow and he didn’t know that danger was right next to him.

Too Brave! Grizzly Bear Risked His Life Attack Lion King To Save His Baby -  Puma vs Bear, Tiger - YouTube
From a distance, the lion is watching the little bear’s every move to see if it’s time to attack immediately.

Bears Vs Lions - Who Would Win?
The time has come, the lion rushed out to chase the little bear, seeing the danger the little bear also began to run, it ran as if calling its mother to rescue him.
The mother bear, who is nearby, sees her cub in danger, then rushes out to fight and survive with the lion to rescue her cub.

BIG MISTAKE LION STEAL BABY BEAR - Mother Bear Save Her Baby From Lion -  YouTube
The mother bear counterattacked very strongly and fiercely, causing the lion to be seriously injured and run away.