[Excerpt] A central conclusion of this report is that firms’ voluntary principles and policies are not enough to safeguard workers’ freedom of association. They can be important initiatives, but only when they contain effective due diligence, oversight, and control mechanisms. Otherwise, as shown here, shortcomings in US labor law create enormous temptation - especially among US managers not sufficiently overseen by European parent company officials - to take advantage of them by acts inconsistent with international norms. The pattern that emerges in the examples presented here suggests inadequate due diligence and internal performance controls to prevent and correct US management actions that run afoul of international standards. Building on prior research by Human Rights Watch and others, this report also gives additional examples of flaws in US labor law that give management the power, in a context of severe disparity in workers’ access to information and the power imbalance inherent in the employment relationship, to use captive-audience meetings, one-on-one anti-union meetings between supervisors and employees, threats of permanent replacement, and other methods permitted by US law to thwart workers’ organizing efforts. In many cases studied here, moreover, the European firms did violate US law. But even if employers cross the line and commit unfair labor practices, US labor law does not provide for penalties or other sanctions sufficient to dissuade repeat violations. At the end of this report, we offer recommendations to European companies to improve their monitoring of US operations to ensure respect for labor rights, to European governments and institutions to improve their oversight of European company labor practices in the United States, and to US lawmakers to bring US law into closer conformity with international freedom of association standards.