The context comes from the movie "Fear And Loathing In Las Vegas" It's a scene in which the main character describes the 1960s
THERE WAS MADNESS IN ANY DIRECTION, AT ANY HOUR... YOU COULD STRIKE SPARKS ANYWHERE. THERE WAS A FANTASTIC UNIVERSAL SENSE THAT WHATEVER WE WERE DOING WAS RIGHT, THAT WE WERE WINNING. AND THAT, I THINK, WAS THE **HANDLE** -- THAT SENSE OF INEVITABLE VICTORY OVER THE FORCES OF OLD AND EVIL. NOT IN ANY MEAN OR MILITARY SENSE; WE DIDN'T NEED THAT. OUR ENERGY WOULD SIMPLY prevail. We had all the momentum; we were riding the crest of a high and beautiful wave...
"handle" noun: : a means of understanding or controlling can't quite get a handle on things(source merriam webster)
Is this the correct def?