This poem is from the Hortulus Carminum Selectorum by Josephus Perez (1627-1694).
Pax Quae Manet
Pax apud aequales longos consistit in annos;
Inter inaequales non manet illa diu.
The vocabulary is keyed to the DCC Latin Vocabulary list. There are two words in this poem that are not on the DCC list:
aequālis, -e (aequālis): equal, even
inaequālis, -e (inaequālis): unequal, uneven
annus -ī m.: year
apud: near, in the presence of (+acc.)
cōnsistō -sistere -stitī: take position; consist (+ abl.)
diū: for a long time
ille illa illud: that
in: in, on (+ abl.); into, onto (+ acc)
inter: between, among; during (+ acc.)
longus -a -um: long, far; longē: far, far off
maneō manēre mānsī mānsum: remain
nōn: not
pāx pācis f.: peace