He knew that was a given.
Check it out:

Secretary of State John Kerry Sunday challenged the notion that President Vladimir Putin went ahead and seized control of Ukraine’s Crimea on the assumption that President Obama would do nothing in response. Russia was not operating from “a position of strength,” he declared.

Appearing on three Sunday talk shows, Kerry said Russia’s actions were reminiscent of 19th century behavior, and warned that possible consequences could include G8 isolation of Russia, visa bans and sanctions.