Technological advancements have augmented the tools at a ruler's disposal to suppress dissent. Digital platforms make dissemination of propaganda easier, allowing for real-time reaction to events. Moreover, advancements in surveillance technology, like facial recognition software and data analytics, enable states to monitor citizens with unprecedented precision. Digital footprints, from social media posts to online transactions, can be analysed to predict dissenting behaviours or affiliations. Furthermore, technology enables cyber warfare, where states can launch digital attacks on opposition platforms, hacking their systems or spreading misinformation. While technology offers manifold benefits, in the hands of authoritative rulers, it's a potent tool to quell opposition.

Yes, states often legitimise suppression by citing external threats. By projecting an image of an imminent external danger, be it from a hostile nation, a foreign ideology, or international groups, rulers can rally the populace around a common cause. This "us versus them" narrative can be used to justify increased surveillance, strict legal measures, and curtailing of civil liberties in the name of national security. Historically, the Cold War era saw both the US and Soviet blocs using the other as an external threat to justify internal policies. Such strategies not only divert attention from internal issues but also foster a sense of unity against a common perceived enemy.

The ethical implications of propaganda largely depend on its content, intention, and outcome. While typically seen in a negative light due to its manipulative nature, propaganda can, in some contexts, be beneficial. For instance, during wartime, it can boost morale and foster unity. Additionally, propaganda campaigns promoting public health, like anti-smoking or vaccination drives, aim for societal well-being. The key distinction lies in whether the propaganda respects individual rights and freedoms, and if it's based on truth. When propaganda serves the genuine interests of society and is transparent in its intentions, it can be perceived as positive. However, it's essential always to approach it with a critical mind.

Prolonged state surveillance can have profound psychological repercussions on citizens. The ever-present "Big Brother" feeling leads to a general atmosphere of mistrust, where individuals are wary of their actions, words, and even thoughts, fearing repercussions. This constant self-monitoring and self-censorship can lead to stress, anxiety, and a general feeling of unease. Furthermore, in a society with extensive surveillance, interpersonal trust diminishes as anyone could be an informant or under state influence. This societal paranoia can erode communal ties, leading to isolation and a sense of alienation. Over time, the mental toll of living under such conditions can be debilitating, affecting overall well-being and mental health.

Rulers have often capitalised on arts and culture to propagate state ideologies. By endorsing specific art forms, literature, music, or theatre that align with state narratives, they subtly influence public opinion. For instance, during the Soviet era, "socialist realism" was promoted, where art was supposed to depict the ideal communist society. This not only showcased the purported benefits of the communist system but also subtly ostracised art forms that contradicted this narrative. Furthermore, state-sponsored cultural festivals or events can highlight national achievements, fostering a sense of unity and pride. Such integration of propaganda into culture makes it less conspicuous, rendering it an effective tool for internal power consolidation.