A key debate of today’s international relations is whether developing powers will accept, reject or modify Western-centered rules, practices and norms. As they rise, developing powers devise strategies to advance interests, influence ongoing negotiations and promote more representative institutions. In spite of this plurality, most works tend to stick definitive criteria to these players’ conducts, opting for static classifications that range from revisionism to status quo. With that in mind, I study how developing powers interact with regimes’ normative and operational foundations, or their principles, norms, rules and decision-making procedures. Focusing on Brazil, this thesis combines within-case and cross case research strategies to investigate how the concepts of concentric circles, responsibility while protecting and right to food respectively engage with the basic components of the regimes of climate change, peace and security and food security. These conceptual contributions are compared in view of three explanatory factors: regime structure, domestic assets and domestic decisionmaking procedures. Original data from in-depth interviews demonstrate that in the time frame 2011-2014 Brazil did not defend alternative views of world order and ordering or expected to harm current norms and principles. Instead, Brazil followed a nuanced approach in its multilateral engagements, expecting to promote specific changes in how regimes’ rules and decision-making procedures should function while keeping normative components in place. Rather than changes of regimes, Brazil therefore hoped for changes within regimes. The research also emphasizes that Brazil’s multilateral behavior is essentially individual and aiming to place the country as a reasonable negotiator in-between developing and developed states. I conclude presenting the concept of foreign policy inertia to explain how Brazil’s activism was possible even in a scenario of mounting economic crisis, lack of presidential diplomacy and reversal of certain domestic assets
