Final answer:
The failure of Kurdish nationalism can largely be attributed to the division of Kurdish lands across multiple countries and the lack of consistent international support due to geopolitical interests and fears of Balkanization.
Step-by-step explanation:
Land distribution has significantly contributed to the failure of Kurdish nationalism due to the division of Kurdish-inhabited regions across several nation-states, specifically Iraq, Iran, Turkey, and Syria. Despite the Kurds having their own language, culture, and identity, their aspiration for an independent Kurdistan has repeatedly been met with violent suppression by these governments, whose territorial integrity would be compromised by Kurdish secession.
The inconsistent international support, especially from the US, which has strategic ties with Turkey and other geo-political interests in the region, has further undermined the Kurdish nationalist movement. Moreover, the global fear of Balkanization and the challenges faced by postcolonial nations with regard to border disputes and ethnic diversity have echoed in the Kurdish experience, as evidenced by the historical reluctance of global powers to endorse separatist movements.