From the war in Ukraine to North Korea's recent missile testing spree, tactical nuclear weapons are being debated and developed in a way not seen since the Cold War.
There is no universal definition of such weapons, and analysts note that the use of any type of nuclear device would break the "nuclear taboo" in place since the United States dropped atomic bombs on Japan in 1945, the only time they have been deployed in war.
Here are the characteristics of tactical nuclear weapons and why they have drawn so much attention.
WHAT IS A TACTICAL NUCLEAR WEAPON?
Tactical nuclear weapons are often characterized by their size, their range, or their use for limited military targets.
They are often referred to as "non-strategic weapons," in contrast with strategic weapons, which the U.S. military defines as designed to target "the enemy’s war-making capacity and will to make war," including manufacturing, infrastructure, transportation, communication systems, and other targets.
Tactical weapons, by contrast, are designed to accomplish more limited and immediate military goals that win a battle.