The Inherent Need for Government Secrecy.
There are many national governments present in the world today that have been elected democratically by the people whom they represent. These governments are directly responsible and accountable to the people, and exist to better the lives of a majority of the people they serve and are chosen by. Being directly responsible to and for the people does not however entail a complete and open honesty with the people of that nation. In many cases it is in the best interest of the nation and its citizens to remain ignorant or purposefully deceived in regards to certain information. This is where intelligence agencies and government security organizations come into play. These organizations specialize in not only acquiring important information, but also in determining what information is suitable for the public at large and in classifying and keeping this information controlled and hidden. It is vital to national security that some information be kept from the public , or even that in certain cases the public be purposefully deceived with certain information. .
A nation's defense forces rely heavily on intelligence and secrecy in performing a number of operations in everything from weapons research to the actual waging and fighting of a war. The information utilized by a nation's defense organizations is necessarily kept private and classified in order to maintain a clear advantage over potential enemies. This information may be in the form of weapons research and development, espionage and reconnaissance information, or in government plans of foreign action to name a few. All of these types of information are necessarily withheld from the public eye to retain and advantage over foreign intelligence services and to maintain national security. .
An example military research being shielded from public access is the ultra-secret Manhattan Project created and carried out before, during and after World War II.