If I play Snapvine targeting an opponent's 3 Might unit and they respond with Smokescreen, will Snapvine trade and/or die?

Ruling: Snapvine will die without killing the 3 Might unit.

Sequence:

• Smokescreen reduces Snapvine's Might to 2
• Snapvine (2 Might) attacks the 3 Might unit but cannot kill it
• The 3 Might unit kills Snapvine in return