PURPOSE: To highlight the degree of perception among the young population in Romania (ages 18–35) regarding the impact of the decisions by some European Union (EU) countries to delay the full acceptance (air, maritime, and land) of Romania’s accession to the Schengen Area on various indicators characterizing the country’s sustainable development, national security interests, and the quality of life of the population. This study was deemed timely in light of the EU’s decision regarding the removal of air and maritime border controls with Romania starting on 31 March 2024 (“Romania’s accession to the Schengen Area, air and maritime”), while maintaining controls at land borders (non-acceptance of “land accession”), under the conditions of Romania fully meeting all the requirements imposed by European legislation, a situation considered by national authorities and the Romanian public as discrimination compared to European states, and causing significant disadvantages in terms of sustainable development and the country’s security interests. METHODS: The study was based on a questionnaire administered to 785 Romanian citizens aged 18–35 years. Data were collected during the period from 15 March 2024 to 15 April 2024, centered around the date of 31 March 2024, which marks “Romania’s accession to the Schengen Area, air and maritime”, through the elimination of EU air and maritime border controls with Romania. The main method used was statistical analysis (descriptive, bivariate, and multivariate), focused on detecting and assessing the degree of respondents’ awareness regarding the efforts of authorities for the full accession of Romania to the Schengen Area and the EU’s response to this effort; the negative impact of delaying the elimination of controls at the EU’s land borders with Romania (“land accession”) on national security interests, on the sustainable development of the country by relating to the objectives of the 2030 Sustainable Development Agenda developed at the United Nations Summit in September 2015, and on the quality of life of people in Romania. Additionally, the study was based on empirical research of the analyzed issues, in accordance with the available literature. RESULTS: The study reveals that, in the context of a very high level of awareness among respondents regarding the efforts of national authorities for Romania’s accession to the Schengen Area (75.26–91.30%) and access to credible information resources and materials about these efforts (65.10–73.05%), Romania’s status as a full-fledged EU member is a determining factor for motivating Romania’s full accession to the Schengen Area (83.33–93.48%). Furthermore, the decisions of some European states to delay full accession are perceived as subjective/unfair actions that are likely to limit/violate the access/facilities of Romanian citizens, as full-fledged EU citizens, to the values of the European democratic space (59.12–76.69%). Additionally, respondents believe that these decisions are likely to affect Romania’s security interests (43.61–56.52%), exacerbate the discrepancies between the living standards of Romania’s population and those of Western European countries (47.59–71.73%), and negatively impact the national implementation of the 2030 Sustainable Development Agenda objectives, as these objectives mostly target significant national infrastructures. Moreover, the WHOQOL-BREF measurement tool shows that these decisions negatively affect, to a large and very large extent, the quality of life of people in Romania (32.07–41.31%), with specific characteristics of the investigated domains (“Physical”, “Psychological”, “Environmental”, and “Social”), depending on the considered socio-demographic variables. CONCLUSIONS: We consider that the study conducted provides a scientifically documented information base regarding respondents’ awareness of Romania’s efforts to join the Schengen Area, their perception of the direct consequences on national security, sustainable development of Romania, and quality of life, as a result of the decisions by some EU countries to delay Romania’s full accession to the Schengen Area. Lastly, the study reveals the correlation between the dissatisfaction/frustration of the population caused by the decision to delay Romania’s full accession to the Schengen Area and the questioning of the social, economic, political, and security consequences induced by this decision.