President Vladimir Putin has warned that Moscow may respond with nuclear weapons if Ukraine, with Western support, strikes deep inside Russia using long-range missiles. This raises critical questions about whether Putin is bluffing. If he is, the West might increase military aid to Ukraine. If serious, the conflict risks escalating into World War Three. Putin extended scenarios for nuclear use, including major cross-border attacks involving Western support. Analysts link his remarks to Ukraine’s lobbying for long-range missiles and President Zelenskyy’s appeals to the U.S.