The International Axion Observatory (IAXO) is a next-generation axion helioscope that will search for solar axions with unprecedented sensitivity. IAXO has a unique position in the international landscape of axion experiments, with sensitivity to a region of the axion parameter space that no other experiment can access. In particular, it will explore QCD axion models in the meV to eV mass range, encompassing models hinted by astrophysics, and potentially also axion dark matter models. IAXO relies on proven solutions and technologies, as well as on the 15-year-long experience with CAST. An intermediate demonstration prototype, BabyIAXO, will further mitigate risk and produce first physics. BabyIAXO is under review now at DESY and will be built and operated in the coming few years, while preparing the ground for IAXO. The scale of IAXO surpasses the traditionally small size of axion experiments and thus requires consideration in the context of the European Strategy.