The statement accurately captures the contrasting perspectives of neo-realism and neo-liberalism on the nature of international politics, with the latter offering a more optimistic outlook on cooperation. Both are rationalist theories, but they diverge significantly in their assumptions about the possibilities for peace and cooperation in an anarchic international system.

Neo-realism (Structural Realism), primarily associated with Kenneth Waltz, presents a 'dark view' of international politics. It posits that the international system is fundamentally anarchic, meaning there is no overarching authority above states. In this self-help system, states are the primary actors, driven by a desire for survival and security. They are inherently suspicious of each other's intentions and constantly seek to maximize their relative power. Cooperation is difficult, fleeting, and always subordinate to security concerns, as states fear being exploited or disadvantaged by others (relative gains concerns). Conflict is seen as an ever-present possibility, and the security dilemma – where one state's efforts to enhance its security are perceived as a threat by others – is a central feature.

Neo-liberalism (Neo-liberal Institutionalism), while acknowledging the anarchic nature of the international system and the centrality of states, offers a 'lighter' or more optimistic perspective. Neo-liberals argue that anarchy does not necessarily preclude cooperation. They emphasize the crucial role of international institutions (like the UN, WTO, or regional organizations) in mitigating the effects of anarchy. These institutions can:

1. Reduce Transaction Costs: Make it easier and cheaper for states to negotiate and reach agreements.
2. Provide Information: Increase transparency and reduce uncertainty about other states' intentions, thereby alleviating the security dilemma.
3. Foster Reciprocity: Create frameworks for repeated interactions, encouraging states to cooperate for long-term absolute gains rather than focusing solely on short-term relative gains.
4. Create Norms and Rules: Establish shared expectations of behavior, making defection more costly.

Thus, neo-liberalism 'lightens' neo-realism's dark view by demonstrating that even self-interested states can find it rational to cooperate under certain conditions, especially when facilitated by robust international institutions. While neo-realism sees cooperation as rare and fragile, neo-liberalism views it as a common and beneficial outcome, leading to a more stable and predictable international environment. It doesn't deny competition but suggests that cooperation can coexist and even thrive within an anarchic system, offering pathways to address shared challenges like climate change, trade, or global health.