Why do countries mutually agree to constraints on their behavior? Why do they comply with such constraints in the absence of enforcement mechanisms? More specifically, why did NATO allies, with disparate geography and perceptions of the international security environment, agree to ‘aim to move towards’ increased defense spending (2% of GDP on defense and 20% of defense budgets on equipment modernization) at their 2014 Wales Summit? Moreover, why have they largely complied with this agreement subsequently? We argue that the ‘Interest Based’ framework for understanding the success or failure of environmental agreements is useful for understanding the agreement and implementation of the Wales Pledge. This argument finds support from interviews with participants and a purpose-built dataset including outcomes of interest (overall defense spending and share of defense budgets allocated to equipment modernization) and key independent variables (vulnerability to security threats and ‘abatement cost’ of meeting the Wales Pledge aims). We find that vulnerability and abatement costs affected both the order in which states agreed the pledge, and the extent to which they have complied with it.

中文翻译：

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设定目标：降低成本、脆弱性和北约威尔士国防投资承诺的协议


为什么各国都同意对其行为进行限制？为什么在没有执行机制的情况下，他们要遵守这些限制？更具体地说，为什么具有不同地理和对国际安全环境看法的北约盟国在 2014 年威尔士峰会上同意“旨在增加”国防开支（国防开支占 GDP 的 2%，设备现代化国防预算的 20%）？此外，为什么他们后来在很大程度上遵守了这项协议？我们认为，用于理解环境协议成败的“基于利益”框架有助于理解威尔士承诺的协议和实施。这一论点从对参与者的访谈和专门构建的数据集中找到了支持，其中包括感兴趣的结果（总体国防支出和分配给设备现代化的国防预算份额）和关键自变量（对安全威胁的脆弱性和实现威尔士承诺目标的“减排成本”）。我们发现，脆弱性和减排成本既影响了各州同意承诺的顺序，也影响了它们遵守承诺的程度。