The iShares U.S. Aerospace & Defense ETF (ITA) is trading at $150.62, down 0.24% as of 10:35 AM ET on November 20th, amid escalating geopolitical tensions and supply chain concerns in the defense sector. The U.S. Embassy in Kyiv was closed following intelligence of a potential air attack, heightening fears of conflict escalation after Ukraine reportedly used U.S.-supplied Army Tactical Missile Systems to strike deeper into Russian territory. This development has led to increased volatility in defense stocks, as the Kremlin's response included changes to its nuclear engagement rules, allowing for nuclear weapon use under certain conditions. Additionally, the U.S. is facing depletion of its high-end munitions due to transfers to Ukraine and Israel, raising concerns about readiness in the event of a conflict with China.