Loads of countries around the turn of the 20th century had Mausers, either locally produced variants or imports. And their use wasn't just limited to state armies either. The Irish Volunteers in 1914 imported a boatload of M1871s from a German arms dealer.
German Mauser was used by Ottoman Armies and Persian ones... so... not difficult to go from Germany to Persia and from Persia to Aghanistan... still in nineties you can find lot of weapons market in Persia... in the Afghan borders!
As I understand it the main advantage of the Mauser over the Krag used by the American regulars was the fast and easy charger (stripper clip) reloading. The Krag was a modern bolt gun with a very smooth and fast action but it had an odd magazine on the side of the receiver which was loaded one round at a time; very fiddly.
The Krags were very well made and are nice to shoot. Many were converted to hunting rifles and the Krag 30-40 round put many a deer on the table.
Note that during the Spanish-American War that while American regulars had the modern Krag rifle many state volunteer troops used obsolete Indian Wars era Springfield black powder breech loading rifles. The "trap door" was an excellent rifle of its type but still...
The Krag-Jorgensen is an interesting rifle and it looks cool. However, the US army began replacing it with the M1903 Springfield in the first decade of the 20th century. The Krag was retained for second line units (engineers, signals and so on) and served through WW I.
The Norwegian army and navy used the Krag in some forms until the 1940s. German occupation resulted in the Norwegian fascists (Quisling security troops) using the Krag after the army surrendered.
The 1903 Springfield effectively was a Mauser, the workings of the rifle being the same. IIRC, the War Dept paid Mauser $1,000,000 for a license to make the rifle, and a royalty was paid for every one built.
I used to have an 03-A3, the simplified WWII version with the rear peep sight. Nice rifle and a real tack driver though somewhat punishing when shooting military surplus ammunition. I preferred my SMLE, made in 1918 at Enfield. Pakistani army surplus .303 was cheap and plentiful at the time and had a gentler recoil than 30-06.