Ukraine on Wednesday lowered the military conscription age from 27 to 25 in an effort to replenish its depleted ranks after more than two years of war following Russia’s full-scale invasion.
The new mobilization law came into force a day after Ukraine President Volodymyr Zelenskyy signed it. Ukraine’s parliament, the Verkhovna Rada, passed it last year.
It was not immediately clear why Zelenskyy took so long to sign the measure into law. He didn’t make any public comment about it, and officials did not say how many new soldiers the country expected to gain or for which units.
Conscription has been a sensitive matter in Ukraine for many months amid a growing shortage of infantry on top of a severe ammunition shortfall that has handed Russia the battlefield initiative. Russia’s own problems with manpower and planning have so far prevented it from taking full advantage of its edge.
As even your Wikipedia article mentions, even though the east of Ukraine hasn’t always been in the same page politically, this separatist movement is fairly new and probably fueled by Russia since at least the 2010s and exploded after the Euromaidan protests .
You can see it by checking the Ukrainian Referendum of Independence of 1991.
https://en.m.wikipedia.org/wiki/1991_Ukrainian_independence_referendum
Only 12-13% in those oblasts voted no, compared to the whopping 42% from Crimea, which is understandable because it was originally Russian territory ceded to the Ukranian SSR by Nikita Khrushchev as a gesture of goodwill (not that it justifies the 2014 annexation it suffered by Russia).
Even though the vote was about leaving the USSR, we can’t separate the Russian question completely from it, and it was an important issue during the referendum.