Large Language Models (LLMs) represent a new frontier of digital infrastructure that can support a wide range of public-sector applications, from general purpose citizen services to specialized and sensitive state functions. When expanding AI access, governments face a set of strategic choices over whether to buy existing services, build domestic capabilities, or adopt hybrid approaches across different domains and use cases. These are critical decisions especially when leading model providers are often foreign corporations, and LLM outputs are increasingly treated as trusted inputs to public decision-making and public discourse. In practice, these decisions are not intended to mandate a single approach across all domains; instead, national AI strategies are typically pluralistic, with sovereign, commercial and open-source models coexisting to serve different purposes. Governments may rely on commercial models for non-sensitive or commodity tasks, while pursuing greater control for critical, high-risk or strategically important applications. This paper provides a strategic framework for making this decision by evaluating these options across dimensions including sovereignty, safety, cost, resource capability, cultural fit, and sustainability. Importantly, "building" does not imply that governments must act alone: domestic capabilities may be developed through public research institutions, universities, state-owned enterprises, joint ventures, or broader national ecosystems. By detailing the technical requirements and practical challenges of each pathway, this work aims to serve as a reference for policy-makers to determine whether a buy or build approach best aligns with their specific national needs and societal goals.

翻译：大语言模型（LLMs）代表了数字基础设施的新前沿，能够支持广泛的公共部门应用——从通用公民服务到专业且敏感的政府职能。在扩展人工智能应用时，政府面临一系列战略选择：是采购现有服务、建设国内能力，还是在不同领域和用例中采用混合方法。这些决策至关重要，尤其当领先的模型提供商多为外国企业，且LLM输出日益被视为公共决策和公共话语的可信依据时。实践中，这些决策并非旨在强制所有领域采用单一方案；相反，国家人工智能战略通常呈现多元化特征，主权模型、商业模型和开源模型共存以服务于不同目标。政府可依赖商业模型处理非敏感或常规任务，同时对关键、高风险或具有战略重要性的应用寻求更大控制权。本文通过从主权性、安全性、成本、资源能力、文化适配性和可持续性等维度评估这些选项，构建了一个战略决策框架。需特别指出，“自建”并不意味着政府必须独立行动：国内能力可通过公共研究机构、大学、国有企业、合资企业或更广泛的国家生态系统来培育。通过详细阐述每条路径的技术要求与实践挑战，本研究旨在为政策制定者提供参考，以判断采购或自建方案何者更契合其具体国情与社会发展目标。