The ongoing digital transformation has begun in electronics and computer sciences, whose innovations were boosted by their applications in National Defense. During the Second World War the advent of computing was fundamental to decrypt German messages, which made possible to shorten the war by at least 2 years and avoid millions of deaths. Digital computers, which registered exponential growth according to Moore’s law, evolved into today’s smartphones, drones, and artificial intelligence. Digitization reduces bureaucratic costs and increases productivity and the speed and precision of response to emerging problems, whatever the sector. In the case of National Defense, there are many application opportunities. This paper presents some vectors for the development and application of information and communication technologies (ICT) associated with the defense industry, highlighting their importance for Portugal. The methodological approach follows the well-known SWOT model where the main strengths, weaknesses, opportunities, and threats are identified. The main goal is to justify the importance of Portugal investing in R&D+i (research, development, and innovation) in defense and security. The study concludes that the Defense Industry is an important vector for the development, not only associated with national security but also to improve the technologic level of Portugal. Sustainability will be achieved by the funding program PRR.