The consequences of cybersecurity attacks can be severe for nation states and their people. Recently many nations have revisited their national cybersecurity strategies (NCSs) to ensure that their cybersecurity capabilities is sufficient to protect their citizens and cyberspace. This study is an initial attempt to compare NCSs by using clustering and topic modelling methods to investigate the similarity and differences between them. We also aimed to identify underlying topics that are appeared in NCSs. We have collected and examined 60 NCSs that have been developed during 2003-2016. By relying on institutional theories, we found that memberships in the international intuitions could be a determinant factor for harmonization and integration between NCSs. By applying hierarchical clustering method, we noticed a stronger similarities between NCSs that are developed by the EU or NATO members. We also found that public-private partnerships, protection of critical infrastructure, and defending citizen and public IT systems are among those topics that have been received considerable attention in the majority of NCSs. We also argue that topic modeling method, LDA, can be used as an automated technique for analysis and understanding of textual documents by policy makers and governments during the development and reviewing of national strategies and policies.