The term 入侵 (rùqīn) carries significant historical and emotional weight in China. The period from the mid-19th to mid-20th century is often referred to as the “century of humiliation” (百年国耻 - bǎinián guóchǐ), a time marked by foreign invasions, unequal treaties, and the ceding of territory. Events like the Japanese invasion during WWII (日本侵华战争 - Rìběn qīnhuá zhànzhēng) are cornerstones of modern Chinese history and national identity. Consequently, 入侵 (rùqīn) is deeply tied to the concepts of national sovereignty (主权 - zhǔquán) and territorial integrity (领土完整 - lǐngtǔ wánzhěng). It evokes a collective memory of vulnerability and the importance of national strength and self-defense. Compared to English, 入侵 (rùqīn) is much stronger than “trespassing” and more specific than “intrusion.” While you might say a journalist's questions are an “intrusion of privacy” in English, the Chinese equivalent would be 侵犯隐私 (qīnfàn yǐnsī), using a related but different word. 入侵 is reserved for large-scale, systematic, and hostile boundary violations, whether it's an army crossing a border, a virus attacking a network, or a foreign species devastating an ecosystem.
入侵 (rùqīn) is a formal word used in specific, serious contexts. Its connotation is always negative.