(a) "Preamble of the UN Charter is representative of the aspirations of humanity in ensuring peace and security across the…

(a) The Preamble opens with "We the peoples of the United Nations" and sets out four aspirations:

• Peace: "to save succeeding generations from the scourge of war";
• Rights: to reaffirm faith in fundamental human rights, the dignity and worth of the human person, and the equal rights of men and women and of nations large and small;
• Justice and law: to establish conditions under which justice and respect for treaty obligations and international law can be maintained;
• Progress: to promote social progress and better standards of life in larger freedom.

It commits the peoples to practise tolerance, unite their strength to maintain international peace and security, and ensure that armed force is not used "save in the common interest". Article 1 turns these into purposes, and Art 2(4) and Chapter VII provide the machinery.

Achievements

• No world war since 1945: great-power war has been avoided for eight decades. The Security Council has authorised collective action (Korea 1950, the Gulf War through Res 678 in 1990). The Uniting for Peace resolution (Res 377, 1950) lets the General Assembly act when the Council is deadlocked, and it was used again for Ukraine (ES-11/1, 2022).
• Peacekeeping: more than 70 operations since 1948, awarded the Nobel Peace Prize in 1988. There have been successful transitions in Namibia, Cambodia, Mozambique and Timor-Leste. India is among the largest troop contributors.
• Decolonisation and self-determination: membership grew from 51 to 193. UNGA Res 1514 (1960) and the Trusteeship system helped end colonial rule, and the Trusteeship Council suspended operations in 1994 after Palau.
• Law and adjudication: the ICJ, ILC codification (VCLT, VCDR, UNCLOS) and the ad hoc criminal tribunals (ICTY, ICTR) have given effect to "respect for obligations arising from treaties".
• Human rights: the UDHR (1948), the two Covenants (1966), CEDAW, the CRC, the Human Rights Council (2006) and the Universal Periodic Review.
• Arms control: the NPT (1968), the Chemical Weapons Convention (1993), the CTBT (1996, not in force) and the TPNW (2017).
• Development and humanitarian work: the MDGs and SDGs, UNHCR, WFP (Nobel 2020), WHO and UNICEF address "social progress". Climate governance runs through the UNFCCC and the Paris Agreement.

Failures and limits

• Veto and selectivity:
• the veto has paralysed the Council over Syria, where Russia and China cast repeated vetoes, and over Ukraine in 2022, when an aggressor permanent member blocked action against itself;
• the Council has also been ineffective on Gaza and Myanmar;
• GA Res 76/262 (2022) now requires a General Assembly debate after every veto, but this is only a political check.
• Atrocities: the UN failed to prevent atrocities in Rwanda (1994) and Srebrenica (1995). R2P (2005 World Summit) has been applied inconsistently, and after Libya (2011) it fell into disfavour.
• Unilateral force: Iraq (2003), and interventions without authorisation, weakened Art 2(4).
• Unrepresentative Council: the Council reflects 1945, not today. Reform through the Intergovernmental Negotiations has stalled despite the G4 (India, Brazil, Germany, Japan) and the African Union's Ezulwini Consensus.
• Resources: a chronic funding and liquidity crisis, worsened by arrears and aid cuts in 2025, has forced retrenchment under the "UN80" reform initiative.
• Enforcement: ICJ judgments depend on State compliance (Art 94(2)). Nuclear disarmament under Art VI of the NPT remains unfulfilled.

Assessment: The UN has succeeded more as a forum, norm-setter and humanitarian actor than as a collective-security guarantor. The Preamble's aspirations remain a normative yardstick. Their fulfilment depends on great-power cooperation, Council reform, financial stability and implementation of the Pact for the Future (2024).

(b) A reservation is "a unilateral statement, however phrased or named, made by a State when signing, ratifying, accepting, approving or acceding to a treaty, whereby it purports to exclude or to modify the legal effect of certain provisions of the treaty in their application to that State" (VCLT Art 2(1)(d)). Its label does not matter. An "interpretative declaration" that in fact modifies obligations is a reservation (Belilos v Switzerland, ECtHR 1988).

Evolution

• Unanimity rule: under the traditional rule, a reservation had to be accepted by all parties.
• Flexible system: the ICJ's advisory opinion in Reservations to the Genocide Convention (1951) replaced unanimity with a flexible system. A reserving State can be a party if its reservation is compatible with the treaty's object and purpose, and each State decides for itself whether to accept or object.
• Codification: the VCLT codified this system (Arts 19–23), and the ILC's Guide to Practice on Reservations to Treaties (2011) elaborates it.

When is a reservation permissible? (Art 19) A State may formulate a reservation unless:

• the treaty prohibits reservations, as with UNCLOS (Art 309), the Rome Statute (Art 120) and the Chemical Weapons Convention for its Articles;
• the treaty permits only specified reservations, and this one is not among them;
• the reservation is incompatible with the object and purpose of the treaty.

The ILC Guide adds that a reservation cannot purport to modify a jus cogens norm (Guideline 4.4.3). However, a reservation to a procedural clause, such as ICJ jurisdiction, is not automatically invalid even if the treaty embodies jus cogens (Armed Activities (DRC v Rwanda), ICJ 2006, on Rwanda's reservation to Art IX of the Genocide Convention).

Acceptance and objection (Art 20)

• Expressly authorised reservations need no acceptance (Art 20(1)).
• Limited-participation treaties, where the treaty's application in full between all parties is essential, require acceptance by all parties (Art 20(2)).
• Constituent instruments of international organisations require acceptance by the competent organ (Art 20(3)).
• Otherwise:
• acceptance by another State makes the reserving State a party in relation to it;
• an objection does not prevent the treaty entering into force between the two unless the objecting State clearly says so;
• a reservation is deemed accepted if no objection is raised within 12 months (Art 20(4)–(5)).

Legal effects (Art 21)

• Between reserving and accepting States: the provision is modified reciprocally.
• Between reserving and objecting States that do not oppose treaty relations: the provisions covered by the reservation do not apply to the extent of the reservation.
• Among other parties: relations are unaffected.

Reservations and objections must be in writing, and a reservation may be withdrawn at any time (Arts 22–23).

Human rights treaties

• Special rules: human rights treaties create obligations towards individuals rather than reciprocal exchanges.
• Human Rights Committee: in General Comment 24 (1994), the Human Rights Committee claimed the power to assess compatibility and to "sever" invalid reservations, holding the State bound without the benefit of the reservation.
• European Court: the European Court applied severance in Belilos and Loizidou v Turkey (1995).
• Pushback: the US, the UK and France objected to this approach.

Indian practice

• ICCPR: India declared that the right of self-determination in Art 1 applies only to peoples under foreign domination. France, Germany and the Netherlands objected to this.
• CEDAW: India made declarations on Arts 5(a) and 16(1) (non-interference in personal affairs of communities) and a reservation to Art 29(1) (ICJ dispute settlement).
• Genocide Convention: India's reservation to Art IX requires the consent of all parties to a dispute before it can be submitted to the ICJ.

(c) General prohibition

• Art 2(4) of the UN Charter prohibits "the threat or use of force against the territorial integrity or political independence of any State, or in any other manner inconsistent with the Purposes of the United Nations".
• Status: this prohibition is customary law (Nicaragua v USA, ICJ 1986), and its core is widely regarded as jus cogens.
• Friendly Relations Declaration: the Declaration (GA Res 2625, 1970) elaborates the prohibition.

Aggression is never permissible

• Definition: GA Res 3314 (1974) defines aggression as the use of armed force by a State against another State's sovereignty, territorial integrity or political independence. Its Art 3 lists acts such as invasion, bombardment, blockade, allowing one's territory to be used for aggression against a third State, and sending armed bands.
• No justification: Art 5(1) of the Resolution provides that "no consideration of whatever nature, whether political, economic, military or otherwise, may serve as a justification for aggression". A war of aggression is a crime against international peace.
• Criminal liability: the Nuremberg Tribunal called it the "supreme international crime". Leaders can be tried for it under Rome Statute Art 8 bis (Kampala, 2010; activated in 2018).
• Rejected justification: Russia's invocation of self-defence and protection of populations for its 2022 invasion of Ukraine was rejected by the General Assembly (ES-11/1, 141 votes). The ICJ ordered Russia to suspend military operations (provisional measures, March 2022).

Force is permissible only within the following recognised exceptions.

1. Self-defence (Art 51)

• The right: there is an "inherent right of individual or collective self-defence if an armed attack occurs", until the Security Council takes necessary measures. Measures taken must be reported to the Council immediately.
• Armed attack: only the "most grave forms" of force, judged by scale and effects, qualify. Mere supply of arms to rebels is not an armed attack (Nicaragua, 1986).
• Necessity and proportionality: these customary limits apply (Nicaragua; Oil Platforms, 2003; Nuclear Weapons AO, 1996). They derive from the Caroline formula (1837): a "necessity of self-defence, instant, overwhelming, leaving no choice of means, and no moment for deliberation".
• Collective self-defence: the victim State must declare itself attacked and request help (Nicaragua).
• Non-State actors: the position is contested. The ICJ has linked self-defence to attacks by States (Wall AO, 2004; Armed Activities, 2005). After 9/11, however, Council Resolutions 1368 and 1373 (2001) recognised self-defence against terrorism. Some States invoke the "unwilling or unable" test, for example for strikes in Syria from 2014. India characterised Operation Sindoor (May 2025), after the Pahalgam attack, as a measured and non-escalatory response against terrorist infrastructure.
• Anticipatory and pre-emptive self-defence:
• anticipatory self-defence against an imminent attack has some support (the Caroline criteria);
• pre-emptive force against remote threats (the 2002 US National Security Strategy; Iraq 2003) is widely rejected;
• Israel's 1981 strike on Iraq's Osirak reactor was condemned by the Security Council (Res 487).

2. Security Council authorisation (Chapter VII)

• Procedure: after determining a threat to the peace, breach of the peace or act of aggression (Art 39), the Council may authorise force under Art 42.
• Examples: Korea (1950), Iraq/Kuwait (Res 678, 1990), Somalia (1992) and Libya (Res 1973, 2011).
• Regional enforcement: regional enforcement action needs Council authorisation (Art 53).

3. Other claimed grounds

• Consent or intervention by invitation: force at the request of a lawful government is permitted, within limits, for example not in a purely internal civil war (ILC Articles on State Responsibility, Art 20).
• Humanitarian intervention: this is not accepted as a legal right. The Independent Commission on Kosovo called NATO's 1999 action "illegal but legitimate". R2P (2005 World Summit Outcome, paras 138–139) channels coercive action through the Security Council only.
• Protection of nationals abroad: for example Entebbe (1976). This is controversial.
• Self-determination: GA Res 2625 recognises that peoples resisting forcible denial of self-determination may seek support. This does not permit other States to intervene with force.

Conclusion: Force is lawful only in self-defence against an armed attack (subject to necessity, proportionality and reporting) or with Security Council authorisation, and consent-based use is lawful within limits. Every other justification is contested. Aggression is never justifiable. It is prohibited, criminal, and a violation of jus cogens.