India, Feb. 13 -- Since late January, when the USS Abraham Lincoln carrier strike group arrived in the Arabian Sea, Washington has maintained readiness for military operations targeting Iran. Faced with internal fragility and the threat of US military action, the Iranian government has sharpened its deterrence signalling. Iran's supreme leader, Ayatollah Khamenei, termed the nation-wide protests as a US-backed coup plot and warned that any attack on Iran would result in a "regional war".

Iran places national independence and resistance to the US at the core of its self-image. While the US calculates that a weaker Iran must make concessions beyond the enrichment issue, including on the range and size of its missile programme and support f...