Nuclear weapons states are strengthening their nuclear arsenals in the face of numerous conflicts worldwide, a leading Swedish think tank on conflict and defence said on Monday. According to a new report published by the Stockholm International Peace Research Institute (SIPRI), the number of operational nuclear warheads is steadily rising. “While the global total of nuclear warheads continues to fall as cold war-era weapons are gradually dismantled, regrettably we continue to see year-on-year increases in the number of operational nuclear warheads,” said SIPRI director Dan Smith. “This trend s…