Trump is a loose canon on deck.
Loose Cannon indeed, and perhaps a good attribute
At the Battle of Trafalgar in 1805 Admiral Lord Nelson devised a tactical device that enabled him with only 27 ships (and smaller) to defeat the 33 larger ships of the Spanish Armada.
As well as his ships being more maneuverable...his cannons, being smaller were more easily aimed for best effect.
I LOVE our “loose cannon”. :-)