poke the bear

The second sense refers to the use of bears to represent Russia, as a shortening of the idiom "poke the Russian bear" (to anger or threaten Russia and start a war with Russia).

poke the bear (third-person singular simple present pokes the bear, present participle poking the bear, simple past and past participle poked the bear)

1. (US, idiomatic) To deliberately aggravate somebody, especially somebody in a position of power or authority.
   • 2012, Marty Makary, Unaccountable, Bloomsbury Publishing USA, →ISBN, page 17:

     Throughout my training I witnessed several doctors run out of town because their honesty and outspokenness began to poke the bear.

   • 2020 October 12, Andrew Marantz, “Why Facebook Can’t Fix Itself”, in The New Yorker‎:

     His advice to Zuckerberg, the Times later reported, was “Don’t poke the bear”—avoid incurring the wrath of Trump and his supporters.

2. (slang, idiomatic) To deliberately anger Russia or the Russian government.

• bearbaiting
• ruffle some feathers
• when you mess with the bull, you get the horns