India poses a significant long-term threat to China. First, India and China have substantial territorial disputes. Second, India's rapid economic growth and immense potential could make it a formidable power by mid-century. Currently, Western nations are accelerating their decoupling from China and relocating manufacturing to India, clearly aiming to mold India into a second China—much like China itself when it first opened up in the last century. This will accelerate India's ascent toward becoming a global power.
In terms of national morality, India has a history of repeatedly encroaching upon China and has even weaponized dams to attack Pakistan. Were it not for China's formidable military strength, India would undoubtedly continue its aggression against neighboring countries. Should such a nation grow powerful, it would pose a grave threat to the world—especially given that India also possesses nuclear weapons.