The IUPF or International Peacekeeping Force was a military coalition that was to fight the Valahia and serves as one of the major factions in Ace Combat X2: Joint Assault
- "That's why the IUPF is made up of PMCs, Olivieri is behind it all!"
- ―Faryd Gaviria, revealing the truth about the IUPF
The IUPF (International Union Peacekeeping Force) was formed by Andre Olivieri of Olivieri Life Insurance after the second attack on Tokyo by the Valahia. It was mainly comprised of PMCs, the most notable of which was Martinez Security.
They engaged the Valahia in numerous places worldwide, including Egypt and the Middle East to rescue a VIP. Then they undertook a simultaneous assault in the Turkish Mountains to destroy the Mora jammers and their high explosive artillery. The IUPF then sent Antares Squadron to engage the Valahia in the Adriatic Sea, where the renegade Rigel Squadron, now calling themselves the Varcolac Squadron was encountered. It was then during the engagement that a Valahia submarine fired the new Hi-TASM, a high explosive AA missile, in an attempt to destroy the IUPF. Despite the dangers of the new weapon, Antares succeeded in destroying the sub. Later on, the Valahia launched the Spiridus to attack London. During the battle, the Spiridus revealed its electrolaser cannons, destroying a section of the city and shooting down 2 of the IUPF's F-14D Super Tomcats. But the Antares managed to evade these terrifying weapons and destroy the fortress successfully. The IUPF then engaged Valahia's Balaur railgun/radar system and disabled their nuclear missiles and HQ, ending the Valahia. However, after the Valahia's defeat, Burford and the Antares Squadron decided to leave the IUPF to fight the Golden Axe Plan.
The IUPF's notable traits are:
- They are mostly comprised of Mercenaries or PMC pilots.
- It is funded by Andre Olivieri, founder of Olivieri Life Insurance and the secondary antagonist of Ace Combat X2.
- It mostly operates around the areas of Central Asia and Europe.