OP I think you've had some good advice already but if you want another tack....
You're both young and whilst it's tough you have many years to "make up" for not seeing each other now.
In WW2 my GM said goodbye to her husband (my GF) who ended up despatched to Burma and they were apart for 5 years.
When the war ended, he and his company had to walk 2000 miles to get the boat home and that took another 5 months.
Today, we have families who can't see elderly loved ones. Families with parents who have dementia and worry they won't even recognise them when they are allowed to visit.
There are those with loved ones desperately poorly and they can't comfort them.
They can't make this time back up - because unlike you/him they don't have "time".
We have families with newborns that their families can't see/support. Instead of that precious cuddle/photo grandparents are making do with online connection and seeing their grandchildren grow over FaceTime.
Is tough, but frankly in the grand scheme of a life (when you're in the prime of it) it's nothing.
A few weeks/months of loss is nothing and as my grandparents found out it solidified their relationship and they never parted again until my GF died after 60 years of marriage.
Other people's sacrifice is much greater - they may never see some people ever again.
If that doesn't convince him, then maybe I'll cite my GM again when I asked her about the best moment in her life when a bit tiddly on the whiskey and she said it was the first night she spent with GF after the war and it was "most pleasurable and satisfying" with a wry wink 