Conscription
The impact is especially severe in wartime, when civilian professionals are forced to fight as amateur soldiers. Not only is the work effort of the conscripts wasted and productivity lost, but professionally skilled conscripts are also difficult to replace in the civilian workforce. Every soldier conscripted in the army is taken away from his civilian work, and away from contributing to the economy which funds the military. This may be less a problem in an agrarian or pre-industrialized state where the level of education is generally low, and where a worker is easily replaced by another. However, this is potentially more costly in a post-industrial society where educational levels are high and where the workforce is sophisticated and a replacement for a conscripted specialist is difficult to find. Even more dire economic consequences result if the professional conscripted as an amateur soldier is killed or maimed for life; his work effort and productivity are lost.

Arguments for conscription: 

Political and moral motives: Jean Jacques Rousseau argued vehemently against professional armies since he believed that it was the right and privilege of every citizen to participate to the defense of the whole society and that it was a mark of moral decline to leave the business to professionals. He based his belief upon the development of the Roman Republic, which came to an end at the same time as the Roman Army changed from a conscript to a professional force. Similarly, Aristotle linked the division of armed service among the populace intimately with the political order of the state. Niccolò Machiavelli argued strongly for conscription and saw the professional armies, made up of mercenary units, as the cause of the failure of societal unity in Italy.
Other proponents, such as William James, consider both mandatory military and national service as ways of instilling maturity in young adults. Some proponents, such as Jonathan Alter and Mickey Kaus, support a draft in order to reinforce social equality, create social consciousness, break down class divisions and allow young adults to immerse themselves in public enterprise. Charles Rangel called for the reinstatement of the draft during the Iraq War not because he seriously expected it to be adopted but to stress how the socioeconomic restratification meant that very few children of upper-class Americans served in the all-volunteer American armed forces.

Economic and resource efficiency: It is estimated by the British military that in a professional military, a company deployed for active duty in peacekeeping corresponds to three inactive companies at home. Salaries for each are paid from the military budget. In contrast, volunteers from a trained reserve are in their civilian jobs when they are not deployed.
It was more financially beneficial for less-educated young Portuguese men born in 1967 to participate in conscription than to participate in the highly competitive job market with men of the same age who continued to higher education.

Drafting of women: Throughout history, women have only been conscripted to join armed forces in a few countries, in contrast to the universal practice of conscription from among the male population. The traditional view has been that military service is a test of manhood and a rite of passage from boyhood into manhood. In recent years, this position has been challenged on the basis that it violates gender equality, and some countries, especially in Europe, have extended conscription obligations to women.
Nations that in present-day actively draft women into military service are Eritrea, Israel, Mozambique, Norway, North Korea, Myanmar,
and Sweden.
Norway introduced female conscription in 2015, making it the first NATO member to have a legally compulsory national service for both men and women. In practice only motivated volunteers are selected to join the army in Norway.
Sweden introduced female conscription in 2010, but it was not activated until 2017. This made Sweden the second nation in Europe to draft women, and the second in the world to draft women on the same formal terms as men.
Israel has universal female conscription, although it is possible to avoid service by claiming a religious exemption and over a third of Israeli women do so.
Finland introduced voluntary female conscription in 1995, giving women between the ages of 18 and 29 an option to complete their military service alongside men.
Denmark will extend conscription to women from 2027.
Sudanese law allows for conscription of women, but this is not implemented in practice.
In the United Kingdom during World War II, beginning in 1941, women were brought into the scope of conscription but, as all women with dependent children were exempt and many women were informally left in occupations such as nursing or teaching, the number conscripted was relatively few.
In the Soviet Union, there was never conscription of women for the armed forces, but the severe disruption of normal life and the high proportion of civilians affected by World War II after the German invasion attracted many volunteers for "The Great Patriotic War". Medical doctors of both sexes could and would be conscripted (as officers). Also, the Soviet university education system required Department of Chemistry students of both sexes to complete an ROTC course in NBC defense, and such female reservist officers could be conscripted in times of war. 
The United States came close to drafting women into the Nurse Corps in preparation for a planned invasion of Japan.
In 1981 in the United States, several men filed lawsuit in the case Rostker v. Goldberg, alleging that the Selective Service Act of 1948 violates the Due Process Clause of the Fifth Amendment by requiring that only men register with the Selective Service System (SSS). The Supreme Court eventually upheld the Act, stating that "the argument for registering women was based on considerations of equity, but Congress was entitled, in the exercise of its constitutional powers, to focus on the question of military need, rather than 'equity.'" In 2013, Judge Gray H. Miller of the United States District Court for the Southern District of Texas ruled that the Service's men-only requirement was unconstitutional, as while at the time Rostker was decided, women were banned from serving in combat, the situation had since changed with the 2013 and 2015 restriction removals. Miller's opinion was reversed by the Fifth Circuit, stating that only the Supreme Court could overturn the Supreme Court precedence from Rostker. The Supreme Court considered but declined to review the Fifth Circuit's ruling in June 2021. In an opinion authored by Justice Sonia Sotomayor and joined by Justices Stephen Breyer and Brett Kavanaugh, the three justices agreed that the male-only draft was likely unconstitutional given the changes in the military's stance on the roles, but because Congress had been reviewing and evaluating legislation to eliminate its male-only draft requirement via the National Commission on Military, National, and Public Service (NCMNPS) since 2016, it would have been inappropriate for the Court to act at that time.
On 1 October 1999, in Taiwan, the Judicial Yuan of the Republic of China in its Interpretation 490 considered that the physical differences between males and females and the derived role differentiation in their respective social functions and lives would not make drafting only males a violation of the Constitution of the Republic of China. Though women are not conscripted in Taiwan, transsexual persons are exempt.
In 2018, the Netherlands started including women in its draft registration system, although conscription is not currently enforced for either sex. France and Portugal, where conscription was abolished, extended their symbolic, mandatory day of information on the armed forces for young people - called Defence and Citizenship Day in France and Day of National Defence in Portugal – to women in 1997 and 2008, respectively; at the same time, the military registry of both countries and obligation of military service in case of war was extended to women.

Conscientious objection: A conscientious objector is an individual whose personal beliefs are incompatible with military service, or, more often, with any role in the armed forces. In some countries, conscientious objectors have special legal status, which augments their conscription duties. For example, Sweden allows conscientious objectors to choose a service in the weapons-free civil defense.
The reasons for refusing to serve in the military are varied. Some people are conscientious objectors for religious reasons. In particular, the members of the historic peace churches are pacifist by doctrine, and Jehovah's Witnesses, while not strictly pacifists, refuse to participate in the armed forces on the ground that they believe that Christians should be neutral in international conflicts.

By country: 

Austria: Every male citizen of the Republic of Austria from the age of 17 up to 50, specialists up to 65 years is liable to military service. However, besides mobilization, conscription calls to a six-month long basic military training in the Bundesheer can be done up to the age of 35. For men refusing to undergo this training, a nine-month lasting community service is mandatory.

Belgium: Belgium abolished the conscription in 1994. The last conscripts left active service in February 1995. To this day (2019), a small minority of the Belgian citizens supports the idea of reintroducing military conscription, for both men and women.

Bulgaria: Bulgaria had conscription for males above 18 until it was ended in 2008. Due to a shortfall in the army of some 5,500 soldiers, parts of the former ruling coalition have expressed their support for the return of conscription, most notably Krasimir Karakachanov.