The legal basis of the European Arrest Warrant (EAW) relies on:
- Treaty on European Union, in particular Article 31(a) and (b) and Article 34(2)(b)
- 2002/584/JHA: Council Framework Decision of 13 June 2002 on the European arrest warrant and the surrender procedures between Member States – Statements made by certain Member States on the adoption of the Framework Decision
The EAW was established in 2002 by a Decision of the Council. It consists in a judicial decision held by a Member State, asking to another Member State to surrender an individual accused of a crime in the former country. The purpose of this instrument is to simplify the procedure of arrest and extradition among the EU countries, without the need of single agreements between MS.
It is important to fix the differences with the traditional way of extradition, that basically concerns bilateral agreement. In analysing the differences it is important to consider:
- the reduction of time: the country hosting the arrested has to adopt the decision in the next 60 days. After the decision no more than 10 days can be effected the delivery.
- The absence of double criminality check for the 32 categories of offences. The 32 elements are contained in a document on which the Member States agreed in 2002.
- There is no more necessity of political intervention, because the decisions are taken at the judicial level.
- As general guideline, the EU states cannot anymore refuse to surrender their own citizens except they will assume their ownership of the execution of the sentence against the wanted person.
- There are also some guarantees, such as the right of the prisoner to ask for a review of the sentence if the punishment imposed is a life sentence; and the prisoner can spend the time in jail in the Executing country, if he has nationality or is an habitual resident.
- There are also limited cases in which a country can refuse to surrender the request, such as: the non-application of the ne bis in idem principle; the criminal has not yet reached the age of criminal responsibility; the application of the amnesty.
The European Arrest Warrant was the result of terrorist attacks after the 11/09/2001. At the beginning this instrument was considered only in order to pursue the crimes that can be considered linked to the terrorism, but then was extended on 32 different crimes.
The list on these 32 subjects is about crimes commonly known as such by all the EU states. The approval of the list of crimes was the result of long negotiation between the 15 MS at the time.
Following a map that shows the number arrests done thanks to this tool. 
Currently under discussion
The current challenges that EU has to face, such as Brexit or the Catalan situation according the extradition of the leader of the protest started in October 2017, put under pressure also the system of EAW.
In the case of Brexit, the hot point is how to manage the issue of the extraditions once that the United Kingdom will be out of the Union, also because UK arrests on EAWs are one of the highest level compared to other MS. According to the result of the negotiations and the following deal, something can change regarding the EAW. 
In the case of Catalan independents leader, Puidgemont, the EAW was requested by the Spanish authority, after his left in Belgium in order to escape the process against him. For the Spanish authority the imputed crimes are rebellion, sedition and embezzlement. The Belgian authority in this specific case has rejected the extradition for two of three pending charges against Puidgemont, saying they are not mentioned in the list of crimes above mentioned. Thus the extradition will be awarded only for the embezzlement, the least serious charge. The Spanish authority so asks for a list reform, saying that it should be updated.
In this quarrel the EU Commission doesn’t accord the reform, because it is possible that further negotiations on the topic can create discontent and move backwards in the purposes already achieved.
In addition, according to Fair Trial organization, the issues that should be solved by the EU Commission are not only in terms of enlarging the sphere of action of the EAW, but on its application. Considering for example the check of proportionality of the judgement and respect of human rights in the prisons.
 EPRS | European Parliamentary Research Service Author: Giulio Sabbati, Members’ Research Service, http://www.europarl.europa.eu/RegData/bibliotheque/briefing/2014/140803/LDM_BRI(2014)140803_REV1_EN.pdf
 Mandato di arresto europeo, come funziona e quali sono i problemi, Lillo Montalto Monella 26/03/2018, https://it.euronews.com/2018/03/26/mandato-di-arresto-europeo-come-funziona-e-quali-sono-i-problemi