What are mixed movements and why do they challenge protection systems?

The concept: the refugee's international protection — the person outside the country fearing persecution: the substitute protection when the state of origin fails (the national protection's breakdown). The nature: a special regime (the refugee-specific rules) built on the human-rights foundation (the general floor) with the humanitarian-law interface (the conflict displacement); the surrogate-protection theory (Hathaway's face). The sources: the 1951 Convention-and-1967 Protocol (the core treaty); the regional instruments (U2's menu); the soft law (the EXCOM conclusions; the UNHCR Handbook); the customary core (the non-refoulement's claimed customarity); the human-rights treaties' complementary application. The scope: the refugee definition-and-status (U3); the rights-and-duties (U4); the solutions (U7) — the displaced-but- excluded faces (the IDPs-and-stateless of 1.4) at the border.