Purpose: This study explores the factors influencing the cross-border purchasing behavior of Vietnamese consumers, particularly for products from the United States and China, in the context of cross-border e-commerce, focusing on distribution channels and international trade dynamics. Research design, data and methodology: The research is based on social identity theory, realistic group conflict theory, cognitive dissonance theory, the SOR model, and the Information Systems Success (ISS) model. From December 2023 to August 2024, a survey was conducted using a seven-point Likert scale, gathering responses from 1,000 consumers in each of the two studies (Study 1 for a U.S. product and Study 2 for a Chinese product). Data was analyzed using partial least squares structural equation modeling (PLS-SEM) via SmartPLS 4.1.0 software. Results: Key factors such as consumer affinity, ethnocentrism, e-service quality, system quality, and information quality influence consumer trust and product judgments. Product uniqueness and price competitiveness were also significant drivers of positive product assessments. Conclusions: This study clarifies how consumer trust and product evaluations influence cross-border purchasing behavior, yielding valuable insights for distribution, logistics, and marketing in international trade. The findings offer actionable guidance for businesses targeting Vietnamese cross-border e-commerce, especially in optimizing distribution channels and improving logistics efficiency.