In TOS, Kirk really didn’t hesitate all. They saw the Klingons were providing muskets and decided to just do it, ostensibly maintain social balance between two groups.

Why Klingons would provide earth-developed weapons is beyond me, but whatever. Kirk has zero coniptions about it- even if he does recognize that it’s wrong (“a hundred serpents for the garden.”)

As for Picard… I would suggest that the prime directive is bullshit, anyhow. Like the non-intervention and no-tech-sharing stuff. It seems more likely to be designed to prevent federation tech from getting into the wrong hands.

Or at least the good stuff likely to be on a feddie warship.