"'Extradition' is the formal surrender of a person by a State to another State for prosecution or punishment." Extradition to or from the United States is a creature of treaty. The United States has extradition treaties with over a hundred of the nations of the world, although there are many with which the United States has no extradition treaty. Extradition treaties are in the nature of a contract. Subject to a contrary treaty provision, federal law defines the mechanism by which the United States honors its extradition treaty obligations. Although some countries will extradite in the absence of an applicable treaty as a matter of comity, it was long believed that the United States could only grant an extradition request if it could claim coverage under an existing extradition treaty. Dicta in several court cases indicated that this requirement, however, was one of congressional choice rather than constitutional requirement. Extradition is generally limited to crimes identified in the treaty. Early treaties often recite a list of the specific extraditable crimes. While many existing U.S. extradition treaties continue to list specific extraditable offenses, the more recent ones feature a dual criminality approach, and simply make all felonies extraditable (subject to other limitations found elsewhere in their various provisions). In addition to an explicit list of crimes for which extradition may be granted, most modern extradition treaties also identify various classes of offenses for which extradition may or must be denied. Common among these are provisions excluding political offenses. The political offense exception has proven troublesome. The exception is and has been a common feature of extradition treaties for almost a century and a half. In its traditional form, the exception is expressed in deceptively simple terms. Yet it has been construed in a variety of ways, more easily described in hindsight than to predicate beforehand. As a general rule, American courts require that a fugitive seeking to avoid extradition "demonstrat[e] that the alleged crimes were committed in the course of and incidental to a violent political disturbance such as a war, revolution or rebellion." Contemporary extradition treaties often seek to avoid misunderstandings over the political offense exception in a number of ways. Some expressly exclude terrorist offenses or other violent crimes from the definition of political crimes for purposes of the treaty; some explicitly extend the political exception to those whose prosecution is politically or discriminatorily motivated; and some limit the reach of their political exception clauses to conform to their obligations under multinational agreements. Separately, several multinational agreements contain provisions that effectively incorporate enumerated offenses into any preexisting extradition treaty between parties. A few of these multilateral agreements also specify that enumerated activities shall not be considered political offenses for purposes of extradition. A number of nations have abolished or abandoned capital punishment as a sentencing alternative. Several of these have preserved the right to deny extradition in capital cases either absolutely or in absence of assurances that the fugitive will not be executed if surrendered. More than a few countries are reluctant to extradite in a capital case even though their extradition treaty with the United States has no such provision, based on opposition to capital punishment or to the methods and procedures associated with execution bolstered by sundry multinational agreements to which the United States is either not a signatory or has signed with pertinent reservations. Dual criminality addresses the reluctance to extradite a fugitive for conduct that the host nation considers innocent. Dual criminality exists when the parties to an extradition treaty each recognize a particular form of misconduct as a punishable offense. Historically, extradition treaties have handled dual criminality in one of three ways: (1) they list extraditable offenses and do not otherwise speak to the issue; (2) they list extraditable offenses and contain a separate provision requiring dual criminality; or (3) they identify as extraditable offenses those offenses condemned by the laws of both nations. Today, as one commentator has pointed out, "[u]nder most international agreements ... [a] person sought for prosecution or for enforcement of a sentence will not be extradited ... (c) if the offense with which he is charged or of which he has been convicted is not punishable as a serious crime in both the requesting and requested state.... " When a foreign country seeks to extradite a fugitive from the United States, dual criminality may be satisfied by reference to either federal or state law. U.S. treaty partners do not always construe dual criminality requirements as broadly. In the past, some have been unable to find equivalents for attempt, conspiracy, and crimes with prominent federal jurisdictional elements (e.g., offenses under the Racketeer Influenced and Corrupt Organizations [RICO] and Continuing Criminal Enterprise [CCE] statutes). Many modern extradition treaties contain provisions addressing the problem of jurisdictional elements and/or making extraditable an attempt or conspiracy to commit an extraditable offense. Some include special provisions for tax and customs offenses as well. As a general rule, crimes are defined by the laws of the place where they are committed. There have always been exceptions to this general rule under which a nation was understood to have authority to outlaw and punish conduct occurring outside the confines of its own territory. In the past, U.S. extradition treaties applied to crimes "committed within the [territorial] jurisdiction" of the country seeking extradition. Largely as a consequence of terrorism and drug trafficking, however, the United States now claims more sweeping extraterritorial application for its criminal laws than recognized either in its more historic treaties or by many of today's governments. Success in eliminating extradition impediments by negotiating new treaty provisions has been mixed. More than a few call for extradition regardless of where the offense was committed. Yet perhaps an equal number of contemporary treaties permit or require denial of an extradition request that falls within an area where the countries hold conflicting views on extraterritorial jurisdiction. The right of a country to refuse to extradite one's own nationals is probably the greatest single obstacle to extradition. The United States has long objected to the impediment, and recent treaties indicate that its hold may not be as formidable as was once the case. A growing number of U.S. treaties go so far as to declare that "extradition shall not be refused based on the nationality of the person sought." Another form limits the nationality exemption to nonviolent crimes. A third bars nationality from serving as the basis to deny extradition when the fugitive is sought in connection with a listed offense. A final variant allows a conflicting obligation under a multinational agreement to wash away the exemption. Even where the exemption is preserved, contemporary treaties more regularly refer to the obligation to consider prosecution at home of those nationals whose extradition has been refused. Depending on the treaty, extradition may also be denied on the basis of a number of procedural considerations. Although the U.S. Constitution's prohibition against successive prosecutions for the same offense does not extend to prosecutions by different sovereigns, it is common for extradition treaties to contain clauses proscribing extradition when the transferee would face double punishment and/or double jeopardy (also known as non bis in idem ). The more historic clauses are likely to bar extradition for a second prosecution of the "same acts" or the "same event" rather than the more narrowly drawn "same offenses." The new model limits the exemption to fugitives who have been convicted or acquitted of the same offense and specifically denies the exemption where an initial prosecution has simply been abandoned. As the Restatement explains, lapse of time or statute of limitation clauses are also prevalent in extradition treaties: Many [states] ... preclude extradition if prosecution for the offense charged, or enforcement of the penalty, has become barred by lapse of time under the applicable law. Under some treaties the applicable law is that of the requested state, in others that of the requesting state; under some treaties extradition is precluded if either state's statute of limitations has run.... When a treaty provides for a time-bar only under the law of the requesting state, or only under the law of the requested state, United States courts have generally held that time-bar of the state not mentioned does not bar extradition. If the treaty contains no reference to the effect of a lapse of time neither state's statute of limitations will be applied. Left unsaid is the fact that some treaties declare in no uncertain terms that the passage of time is no bar to extradition, and others rest the decision with the discretion of the requested state. In cases governed by U.S. law and in instances of U.S. prosecution following extradition, applicable statutes of limitation and due process determine whether preindictment delays bar prosecution and speedy trial provisions govern whether postindictment delays preclude prosecution. A foreign country usually begins the extradition process with a request submitted to the State Department sometimes including the documentation required by the treaty. When a requesting nation is concerned that the fugitive will take flight before it has time to make a formal request, it may informally ask for extradition and provisional arrest with the assurance that the full complement of necessary documentation will follow. In either case, the Secretary of State, at his discretion, may forward the matter to the Department of Justice to begin the procedure for the arrest of the fugitive "to the end that the evidence of criminality may be heard and considered." The United States Attorneys' Manual encapsulates the Justice Department's participation thereafter in these words: OIA [Office of International Affairs] reviews ... requests for sufficiency and forwards appropriate ones to the district [where the fugitive is found]. The Assistant United States Attorney assigned to the case obtains a warrant and the fugitive is arrested and brought before the magistrate judge or the district judge. The government opposes bond in extradition cases. A hearing under 18 U.S.C. §3184 is scheduled to determine whether the fugitive is extraditable.