‘Western Christian’ is a geopolitical category, not a religious one.

Evidence

Here it is important to remember that ‘Western Christian’ means ‘born in one of the Western countries traditionally considered Christian’ and may include professed atheists and religious fanatics alike. — Norman Daniel, Islam and the West, 1715

Categorization

• DEFINE: Defines ‘Western Christian’ as birth/civilizational category that retains its force even for atheists.
• XREF: Strongly parallels the vault’s treatment of Islam as a constructed civilizational marker cloven from a secularized ‘West’ — cf. Anidjar’s genealogy.