The problem is indeed lack of forces on the front lines. But lowering the so-called age limit of mobilization is not the solution.
The perception of a high age limit is not due to a hard limit. It is most likely due to reservists being mobilized in order of experience.
Mobilization goes in waves: operational reserves, then former military personnel, then those who have had military training. Only then do they call on the general public. Naturally, those with more experience are going to be older.
Recently (July 2024) they have improved their voluntary registration process and have recently signed up 2 million reservists. So anytime you hear about people being “taken” by police for “dodging the draft”, they are reservists who have not registered.
The number of reservists registered is satisfactory (with another 4 million allegedly available before needing to conscript the public in general).
When the war began there were more than enough volunteers even signing up to satisfy the defense force’s needs.
And this is speculative, but based on anecdotal accounts, there is a general desire to avoid mobilizing younger men because many have not had a chance to start families yet. Additionally I speculate that the older generation would rather the younger generations not be exposed to the horrors of war if not necessary.
I want to also address the more recent decrease in volunteers and the reluctance of some reservists to register. This reluctance is of course real and common in any war that lasts more than a year.
The reluctance has been exacerbated by the lack of a strong demobilization strategy. When the invasion began in 2022, the government was not ready to fight an extended full scale existential war for three plus years and the time limits in mobilization were not made clear.
And recently the new mobilization law has still failed to require a number of longer term contracts for professional soldiers (i.e. those who are less worried about a separate career or starting a family). And it also failed to specify a time limit for mobilization of non operational reserves or volunteers.
In other words, volunteering and registration have decreased because it is unclear how long the war will go on. And for many of those, it means putting a family or career on hold indefinitely. But again they have enough soldiers, which brings the most important point.
The reason that there is a manpower shortage on the front lines is that they simply cannot arm everyone. They lack the weapons, vehicles and ammunition to fully equip the men they have:
There are still more than 30 territorial defence brigades in the Armed Forces, armed only with small arms and mortars, although they could be transformed into full-fledged mechanised brigades if they were to be provided with armoured vehicles, artillery, electronic warfare equipment and so on. The insufficient amount of weapons and military equipment is also a problem for regular brigades. For example, the 14 reserve brigades created by Ukraine cannot be used in combat zones due to the delay in the delivery of equipment that was promised by partners.
Requiring Ukraine to lower the age limit of conscription in order to continue receiving aid is a somewhat misleading demand. It appears to be more of a political posturing than a reasonable demand; regardless of motivations for making it, the result is the spreading of the false impression that Ukraine is running out of men.
Via RUSI