Who strike at our friends strike us as well

This is from the song Denmark 1943, about the evacuation of Danish Jews before the Nazis enforced their edict to deport them to the concentration camps.

{Refrain}
And it's fire up the diesel and look out for swells
We're leaving Espergaerde behind us
Who strike at our friends strike us as well
We'll pray the patrol boats don't find us
When the sirens are wailing and shouts fill the night
Never will you stand alone
So it's over the Øresund
Till the day we can welcome you home

That this was written and sung by a lefty, liberal, Reverend Fred Small, doesn't distract me from the power of the song. I choose to ignore that about him. The example of the Danes is a trait to be emulated.

If you strike our friends, you strike us as well.

When the time comes, how can we stand by and do nothing?