Which criterion is commonly used by states to justify travel restrictions against another nation’s citizens?

💡 Explanation:

Sovereign nations often impose travel restrictions or visa sanctions citing national security, public safety, and immigration enforcement concerns. Key justifications include a lack of sufficient information for vetting, widespread corruption leading to unreliable civil documents, or refusal by the foreign government to accept the return of its citizens who are subject to deportation. This directly relates to 'inadequate cooperation on vetting or document integrity.'