"push comes to shove" uttryck

vad betyder uttrycket egentligen? vad syftar det på?

UD förklarar det såhär, vilket jag till hälften kan hålla med om:

When the position you're in is so disastrous that something has to be done to improve it. Otherwise it may come to an end.

"Freddie and Fannie... yet have survived under the implicit understanding that the US Government will always bail them out if push came to shove..."

Hittade denna definition.
if/when push comes to shove
if you say that something can be done if push comes to shove, you mean that it can be done if the situation becomes so bad that you have to do it Look, if push comes to shove we'll just have to sell the car.

Det betyder = när det verkligen gäller.

Ja, som Nas’ rader i One love:

You was my nigga when push came to shove.
One what? One love.