Treaty Obligations, Credible Threats, and Modern Warfare

An analysis of treaty obligations in international law through the lenses of preemptive strikes, the war in Ukraine, and the Nicaragua v. United States case.

1. Foundational Treaty Obligations: The Prohibition on Force

The cornerstone of international peace and security is Article 2(4) of the UN Charter, which prohibits the threat or use of force against the territorial integrity or political independence of any state. This is considered a peremptory norm (jus cogens).

Exceptions to this prohibition are: (1) Authorization by the UN Security Council under Chapter VII, and (2) The inherent right to individual or collective self-defense under Article 51 in response to an "armed attack."

2. Preemptive Strikes and "Credible Threats": Israel vs. Iran

The doctrine of anticipatory self-defense allows for preemptive force against an imminent armed attack, but its application is highly contentious.

The concept of a "last window of opportunity" has emerged, arguing that imminence should be based on the irreversible intent and capability of an adversary, particularly regarding WMDs, rather than a purely temporal factor. This was a key justification for analyzing Israel's potential Operation Rising Lion against Iran's nuclear facilities.

However, such actions face major challenges, including the subjectivity of defining "imminence" and the common failure to submit a proper Article 51 notification to the UN Security Council.

3. Warfare in Ukraine: Treaty Violations and Hybrid Threats

The Russian invasion of Ukraine constitutes a clear violation of Article 2(4) of the UN Charter. Its actions also breach the Geneva Conventions and other treaties like the Chemical Weapons Convention.

Russia's use of hybrid warfare—including cyberattacks, disinformation, and sabotage—creates "credible threats" that blur the lines of attribution and challenge traditional legal frameworks for self-defense and countermeasures.

4. The Nicaragua Civil War and US Obligations

The ICJ's ruling in Nicaragua v. United States (1986) is a seminal case on intervention and treaty law. The Court found the U.S. in violation of:

• Customary international law principles of non-intervention and non-use of force.
• Specific treaty obligations under a 1956 Treaty of Friendship, Commerce and Navigation.

The case established the high threshold of "effective control" for attributing the conduct of non-state actors (like the Contras) to a state. It also highlighted the enforcement deficit in international law, as the U.S. refused to participate in the proceedings and blocked compensation in the UN Security Council.

Comparative Legal Analysis

Case/Doctrine	Key Treaty Obligations & Principles	Criteria for Lawful Action	Major Challenges
Nicaragua v. US	UN Charter Art. 2(4); Customary law (non-intervention); Bilateral treaties	Necessity & Proportionality; "Armed Attack" requirement for self-defense	Attribution ("Effective control" test); Enforcement (UNSC veto)
Preemptive Strike (Israel-Iran)	UN Charter Art. 51; Customary law (imminence, necessity, proportionality)	"Last window of opportunity"; Exhaustion of diplomacy; Proportional targeting	Subjectivity of "imminence"; Failure to report under Art. 51
War in Ukraine	UN Charter Art. 2(4); Geneva Conventions (IHL); Chemical Weapons Convention	Right to self-defense (& collective); IHL principles (distinction, proportionality)	Hybrid warfare blurring attribution; Disinformation campaigns

Conclusion: The Evolution of Credible Threats and Treaty Compliance

Treaty obligations provide the critical framework for regulating force, but their effectiveness is constantly challenged by evolving security threats like hybrid warfare and WMD proliferation. The core principles of necessity, proportionality, and imminence remain essential for any lawful claim to self-defense. However, strengthening compliance requires greater political cohesion among states to address the enforcement deficit in the international system.