Network perspectives can be useful but require further development. Scholars seem simply to assume the presence and importance of policy networks. It is important, therefore, to investigate instances in which policy networks are absent - or present but exhibit structural 'gaps'. Such inquiries can help to clarify the value of the network notion for explaining policy dynamics. This study provides such an opportunity. The investigation focuses on policy implementation for controlling air pollution in Hungary, as organized through the so-called international acidification regime. The case covers an effort to execute continuing and increasing policy commitments amidst dramatic political and economic change. The Hungarian implementation context exhibits a number of gaps or network failures which contribute to underperformance in this sector. Successful program implementation, at least in some fields, requires a recognition that networks are important but do not inevitably develop to fulfill implementation requirements.