The New York Times reports that Defense Secretary Lloyd Austin will be deciding “in the next few days” whether to recommend mandatory COVID-19 vaccinations for active duty members of the military. Biden had asked the military to draw up plans for adding the vaccine to the list of required military vaccinations just last week, which suggests Austin is moving forward at an aggressive clip.

In practice, it’s almost certain that the military will mandate universal COVID-19 vaccines within the next few months. The only remaining question is timing. The currently available vaccines have been authorized by the Food and Drug Administration (FDA) for use only on an emergency basis, but full FDA approval for some may happen in as early as one month. The decision being contemplated in the meantime is whether the pandemic represents enough of a threat to military forces to justify a vaccination mandate before full FDA approval is granted. That would require an order by President Biden himself; whether or not to recommend Biden do so is the decision Austin is mulling over right now.

The risk the pandemic poses to U.S. armed forces was made clear early on in the pandemic when the nuclear aircraft carrier USS Theodore Roosevelt was idled due to rampant onboard spread of the virus. But the ship’s captain was relieved of duty after messages he wrote pleading to his superiors for help in quarantining his crew—messages that embarrassed a Trump White House that had been working aggressively to downplay the significance of the pandemic.

Embarrassing to the White House or not, the incident drove home how quickly the COVID-19 virus could disrupt military operations reliant on crews working in close quarters and for long periods of time.

Those dangers have not yet abated. The delta variant of the virus appears to be significantly more contagious than previous iterations, allowing it to spread even more quickly. It appears to have the ability to sometimes spread even among asymptomatic, vaccinated hosts, further increasing the risk to the unvaccinated.

With many millions of vaccinations now completed, there continues to be vanishingly few reported cases of serious side effects, and full approval of multiple COVID-19 vaccines now appears almost certain. The military, much like the other federal agencies grappling with the effects of the pandemic, must now decide whether the possibility that future side effects will be discovered outweighs the known serious risks of COVID-19 infection now.

But the two risks have this point have been well documented and aren’t even comparable, so it’s almost certain that the military will, indeed, issue orders for mandatory vaccinations on the speediest possible timeline. Losing soldiers to a pandemic is expensive, if nothing else. The military does not train top-notch experts in narrow but vital fields for those experts to be done in by an enemy smaller than a mote of dust. There’s simply no plausible justification for not requiring the COVID-19 vaccine (and, likely, future boosters) to the list of already mandated vaccines that keep measles, chickenpox, and other potentially deadly superspreaders at bay. Austin’s speed on this one suggests that the military is keen on getting this done as soon as possible.