2.1 Substantive Principles

2.1.1 Principle of Good Neighborliness: the state's duty to use its territory without harming the neighbours — the neighbour-law of nations (the Trail Smelter's spirit; the UN Charter's Article 74's face); the cooperation's positive duty (the shared resources' joint management). 2.1.2 Duty to Avoid Environmental Harm (No Harm Principle): the customary core: no state may cause significant transboundary environmental harm — the due-diligence standard (the conduct's reasonableness, not the result's strict guarantee); the principle's treaty-career (the Stockholm Principle 21, the Rio Principle 2); the liability's backbone (the breach → the state responsibility). 2.1.3 Prevention Principle: the ex-ante logic: the harm prevented is cheaper-and-better than cured — the assessment-before-action (the EIA's philosophical base); the preventive measures' priority over the end-of-pipe (the cleaner-production faces). 2.1.4 Precautionary Principle: the uncertainty's rule: the serious-or-irreversible threat → the preventive action despite the scientific uncertainty (the burden shifted to the risk-creator); the Rio Principle 15's formulation (the cost-effectiveness qualifier); the contest (the science-vs- precaution debates — the technology disputes' home). 2.1.5 Polluter Pays Principle: the cost internalisation: the polluter bears the prevention-and- remediation costs (not the society-nor-the-state) — the economic instruments' philosophy (the taxes, the charges, the deposits); the Nepali reception (the EPA 2076's compensation-and- pollution-charge faces; the Godavari line's compensation ideas — Unit 6). 2.1.6 Intergenerational Equity: the time-justice: the future generations' rights — the…