C2 Reading Test – Quantum Technologies & Strategic Stability

Read the passage (~420 words) and choose the best answer (A–D).

“Quantum advantage” is often discussed as a laboratory milestone, but its geopolitical consequences depend on where advantage appears first. Quantum sensing could detect submarines at longer ranges or map underground facilities with unprecedented precision; quantum communication promises tamper-evident links; and quantum computing threatens widely used cryptography if large, fault-tolerant machines arrive. Each capability tugs on a different thread of strategic stability—the set of expectations that keeps rivals from racing to pre-emption.

Paradoxically, the most mature quantum tools may be the most destabilizing. If quantum sensing degrades stealth, a state may fear that its second-strike assets are becoming targetable, which tightens decision windows in a crisis. Conversely, quantum key distribution (QKD) might reassure leaders that command messages will not be forged, yet QKD does little to authenticate who is sending the message; it secures the pipe, not the politics. Computing timelines are even murkier: “store-now, decrypt-later” incentives already push adversaries to hoover up encrypted traffic in case future machines can break it, while defenders scramble to migrate to post-quantum cryptography whose real-world performance and interoperability are still being proven.

Stability hinges on signals and verification. Deterrence relies on credible capabilities that are also legible enough to adversaries. But quantum systems resist easy signaling: classified sensor ranges, fragile labs, and export controls make demonstrations rare; meanwhile, exaggerated public claims can mislead both domestic audiences and rivals. The result is an unstable mix of secrecy and hype that can distort procurement and fuel arms-race narratives.

A second stressor is asymmetric benefit. Quantum sensing is mostly a public-good problem for submariners—one actor’s gain is another’s exposure—whereas post-quantum cryptography can, in principle, help everyone. Policymakers therefore face a portfolio choice: hedge against worst-case breakthroughs without letting low-probability scenarios cannibalize budgets for near-certain needs (resilient comms, space situational awareness, cyber hygiene). The prudent path is robust hedging: dual-track investments that deliver value even if quantum timelines slip—e.g., crypto-agility, diversified basing modes, and verification regimes that do not depend on any single sensing modality.

Finally, governance must evolve. Confidence-building measures could include reciprocal transparency on post-quantum migration, shared test ranges for benign quantum sensors, and crisis hotlines that isolate nuclear command from experimental networks. None of these fixes the physics, but they widen decision time and reduce misinterpretation. Quantum technology does not abolish strategic logic; it rearranges it—pressing states to relearn old lessons about signaling, redundancy, and the politics of uncertainty.