Biological threats—natural, intentional, or accidental—in any country can pose risks to global health, international security, and the worldwide economy. Because infectious diseases know no borders, all countries must prioritize and exercise the capabilities required to prevent, detect, and rapidly respond to public health emergencies. Every country also must be transparent about its capabilities to assure neighbors it can stop an outbreak from becoming an international catastrophe. In turn, global leaders and international organizations bear a collective responsibility for developing and maintaining robust global capability to counter infectious disease threats. This capability includes ensuring that financing is available to fill gaps in epidemic and pandemic preparedness. These steps will save lives and achieve a safer and more secure world.