Canada pulls ambassador from Moscow over Ukraine

[The Straight Story]

OTTAWA (AP) — Canada says it is pulling its ambassador from Moscow over the crisis in Ukraine.

A statement issued by Prime Minister Stephen Harper after an emergency Cabinet meeting says Canada also is pulling out of the Group of Eight process being chaired by Russia for an international economic summit in June.

Harper strongly condemns Russia's military intervention in Ukraine and urges President Vladimir Putin to withdraw his troops.

International pressure is growing on Russia after its troops took over the strategic Crimea region Saturday. Russia's parliament granted Putin authority to use the military to protect Russian interests in Ukraine, where a new government has been named after demonstrations pushed President Viktor Yanukovych from office.

http://bigstory.ap.org/article/canada-pulls-ambassador-moscow-over-ukraine

[Vox Moi]

1. Why do nations recall ambassadors?

It seems like a childish threat. "Oh Yeah? … Well, I'm not talking to you any more. So there."
I know it's for dramatic effect but still it seems like a strange strategy for conflict resolution.
You can't apply pressure without a point of contact. If that contact is not diplomatic then is is far more likely to be military.