Taking into consideration Ash’s critique, I’ve toned down the mysterious nature of the disappearances. Now it’s framed as an epidemic of injustice and slavery exacerbated by the lack of a new Jedi Order. I’ve also reverted the first line to the original, since it’s actually quite good.

Luke Skywalker has vanished.
In his absence, the power
of the Jedi Knights has
faded into legend.

Slavery and injustice now
stalk the galaxy, fueling
a new Imperial regime.
With the ability to realize
its grandest designs, this
FIRST ORDER moves
to destroy the allies of
the Jedi wherever they
are found.

While the Republic strives
for a diplomatic solution,
a few bold senators fund a
covert RESISTANCE to
counter these attacks and
find their guardian of
peace and justice amid
the endless stars…

I also realized that there was an easier way to clarify the Republic’s role: Simply have it fight on a different battlefield. The fact that there are no diplomatic solutions don’t completely negate the value of its attempts.

LATE JEDIT: One of the reasons I’m having such trouble writing this crawl is that I don’t want to make it sound like the First Order was a recent occurrence. In the original crawl, it sounds like the First Order arose after Luke vanished, only a few years before the start of the movie. Here’s an attempt at uncoupling the First Order from Luke’s recent activities:

The Jedi Order has fallen.
Betrayed by his students,
the famed Luke Skywalker
has vanished into exile.

Vowing to destroy their
master once and for all,
these evil warriors have
allied with the sinister
FIRST ORDER, a regime
born from the fallen
Empire and concealing
a weapon of devastating
power.

Fearing to take action
that would lead to war,
a few brave senators in
the new Republic fund
a covert RESISTANCE
to find their guardian of
peace and justice amid
the endless stars…