Prospicimus modo quod durabunt faedera longo
Tempore, nec nobis pax cito diffugiet.

That means “We foresee now that the confederacy shall last a long time, and that peace will not quickly fly away from us.” But reverse it:

Diffugiet cito pax nobis, nec tempore longo
Faedera durabunt, quod modo prospicimus.

and it means “Peace will soon fly away from us, and the covenant shall not last long, which we foresee already.”

See also A Bilingual Palindrome.