Ha ha ha, I actually spent some time considering whether or not to use that expression at all. I was going to make a more obscure pun about spilling tea incorporating your quest for tea, but then I remembered what sub this is and decided to sit the split the difference and use it in a way the context will hopefully give it away. I’m glad I didn’t go with my instinct for terrible jokes and muddy the message!
“The side that stays within its fortifications is beaten”
Napoleon Bonaparte
Not only do you need to strike at the enemy’s territories and hold it to win, you need to threaten to keep it if you want to restore your original borders. Going to the peace table with enemy cities your pocket is a classic way to negotiate for your own land back. The more Russian land the Ukranians take, the more likely we will see a restoration of old borders.