On the face of it, Canada - which sells 70% of its goods to the US, the world's biggest economy - may not appear to have much room to manoeuvre in the escalating trade fight between the two countries. But as our Canada digital editor Jessica Murphy explains, it actually holds some pretty powerful cards, with it being the top customer for more than half of all US states. A decision by most provinces to ban American alcohol from its store shelves has already hurt that industry, and Canada is the top trading partner for more than half of all American states. Plus, Canada supplies the vast majority of US natural gas and electricity imports - and officials have said squeezing America on energy hasn't been ruled out. Ottawa will announce its next moves later today - so watch this space.

After the US unveiled what it called "economic D-Day" targeting countries and banks dealing with Iran, Tehran said it was "fully prepared" for the sanctions. "We know how to play the game," its economy minister said. Now, the big questions: will these latest sanctions be effective and how will China, the biggest buyer of Iranian oil, react?

When you tip at the end of the meal, your generosity isn't guaranteed to trickle down to the staff back in the kitchen. That's why Massachusetts noodle bar owner Rachel Miller scrapped the practice and raised her restaurant's prices instead to pay her workers higher wages. Meanwhile, San Francisco wine waiter Caroline Kraetzer says it is good to no longer be "reliant on the generosity of strangers to pay the bills" after her workplace banned tips and started charging higher prices - but not all customers welcome the move, despite growing evidence of "tip fatigue".