Strategic weaponry

"Strategic weaponry" means large-scale weapon used to change the course of a conflict. These can mean different things in different venues.

On the Ground

In ground-based combat, strategic weapons most often refers to Nuclear Ordnance, more specifically the N1.5 varriant that can render very large portions of a country completely uninhabitable.

Space

In space, it most often--but not always--refers to the Nova Bomb. Though mainly known for its ability to destroy a star or planet, Nova weapons can actually be used in space much the same way hydrogen bombs are employed on a planet: to render large areas temporarily uninhabitable. The residual heat and radiation will typically be too much for the standard shielding of most vessels. This can effectively cordon off a portion of space for days or even weeks.

Other

The term is often used in reference to an over-all strategy, where part of the plan involves forcing the enemy to make a certain move. Somtimes only the threat of strategic weaponry is used, other times the weapons themselves are aimed at seemingly inconsequential targets as a show of force or to drive the enemy into a more advantagous location.