There are different Kinds of defense available to the defendants in a civil litigation among which the counterclaim is of high importance. The simultaneous settlement of several but dependent and linked disputes between the parties to the litigation and consequently avoidance of contradictory judgments are the considerable advantages of counter claim. Based upon the above, the important is to bear in mind the concept and nature of the counterclaim as well as the preconditions to raise it. To this end, this essay is trying to elaborate the concept of counterclaim and to pose some new questions on the subject with due regards to the legal atmosphere of Iran.

Just and essential proceedings by the considering authority requires to comply with trial principles, a matter that has been accepted by the Judicial Authorities. In the Arbitration Authorities also due to Judicial function of arbitration work the observance of trial principles is necessary contrary to arbitration formalities. One of the principles binding by the Arbitration Authority is the acceptance of lodging counterclaim by the respondent. Comparative study shows that unlike other countries that legislated this matter, in Iran not only the legislator but also jurists did not pay noteworthy attention to this topic. Regarding the counterclaim in arbitration it is to be said that this claim is admissible when it is in the scope of arbitration agreement or clause. In addition to the conditions of counterclaim the said claim is acceptable when there does not exist its barriers. Set-off also is dependent on the claim and with restitution of claim the set-off is discarded. Moreover, the mere restitution of original claim will not render the termination of counterclaim which is under consideration.

To identify the subject of this Article, the pure defense first must be separated from hybrid counterclaim. Hybrid counter claim has a dual function: the first aim of this claim is to reject the adversary claim. On the other hand, as similar as the pure counterclaim, it renders a claim, out of the object of principal claim. In Iranian Law, some proving criteria have been rendered by legal writers to distinguish these two judicial acts. In these theories the probative value of the defendant’s documents, determine the necessity of filing a counterclaim. Upon analysis of this paper, the proving criteria in theory and practice are not convincing for distinction of counterclaim from merit defense. Criterion accepted in this Article is that in counterclaim, the defendant claim to get a profit other than mere reject of adversary’s claim. In spite of apparent simplicity of this criterion of distinction of counterclaim from merit defense, its practical application is not without complexity.

Claims in courts are reviewed and the procedures and their characteristics and characteristics are one of the structures of civil law science. Examination of conflicts between the two sides of the dispute and the consideration of the quantitative and qualitative structure of the existing cases and the claims of the parties to the civil litigation from the criteria of the dispute Mutual in civil procedure. Justice The judicial review process requires two relevant legal cases to guide the exchange of these demands and claims to a more precise structure of the implementation of civil justice. Comparing and adapting the characteristics of mutual claims and using the best methods for better implementation of justice and fairness in civil cases. The aim of this article and the desirable purpose of the comparative study of counter-actions in Iranian and American law is. In this research, the author has used a descriptive-analytical and librarian approach and studies the internal and external resources. An examination of the comparison of cross-claims in two different systems of Iran and the United States in order to establish a precise and complete interrogation clause and Ultimately, there is a reduction in the number of prosecutions and a reduction in the number of cases in the justice system and better justice.

Investment arbitrations have their own challenges due to their asymmetric nature, which arise from the essential difference between the parties to the claim. The investor on the basis of the investment agreement can bring a claim against the host State, but on the contrary, the counterclaim by States for changing the current process of investment arbitration, in which the ultimate conviction is usually for the State, faces with a number of fundamental challenges. This is due to the non-anticipation of the possibility of counterclaim by States and the difficulty of imposing the obligations of international law on investors. These gaps along with the possibility of violation of human rights by the investor, ultimately, lead to non-compensation of third-parties, who are in many cases the direct victims of human rights abuse in this process. Urbaser v. the Argentina is the first ICSID case which the ICSID arbitration tribunal accepts a counterclaim of a State based on human rights violations and puts it into detail analysis; although finally the State remained unable to prove its claim, and the counterclaim had been rejected in merits.

In order to eliminate the deficit and develop international law, it has been always adapted from municipal law by reliance to the principle of analogy. Positivism opposes this approach, but this is reality that international law is not an integral part of municipal law. Counterclaim before international court of justice support from respondent and enforcement of justice. The Court will issue the decision of counterclaim provided that it comes within the jurisdiction and direct connection with the subject-matter. The precedent implies that the international court of justice adheres to formalism. Although The Court has sometimes abandoned from strict position to the condition of direct connection, but it has still been bound to jurisdiction even in cases where the nature of the claims ware erga omnes by positivist approach.

Judgment is the most important output of a judicial system. It is the most valuable document and the most complete proof, reflecting the truth hidden in the case in question, especially if a decision is expressed in the form of a” judgment on the merits” on the case, decisively ends the dispute and expresses the judge's final opinion regarding the nature of the case (Article 299 of the Iranian Civil Procedure Code). This task has been given to the courts and it is the real mission and the main project of the Judiciary. Review of a judgment, delineating its strengths and sometimes its shortcomings and inadequacies, is the best assistance one can render the administration of justice. Based on this belief, I have gone to a judgment that is highly worthy of criticism. Non-existences, deficiencies, shortcomings and inadequacies are evident in this judgment. A Judgment that ends a dispute relying the efforts of multiple people through several original and ancillary claims, but fails in its main mission. In this short research, first the text of a judgment, then its writing inadequacies and substantive challenges are mentioned. In the midst of this discussion, the essential elements in making a magnificent, useful and worthy judgment shall be set forth.

Relation between litigations has a significant effect on process and judgment. Except its definition, legislator has not indicated concrete criteria of the relation for its recognition. In this study, we have studied six criteria including Co-Relationship and Mere Relationships; One-way Relation and Two Way Relation; Proof Relation and the effect of judgments; Res judicator; Indivisibility of Claims and interdiction of twice condemning. The source of these six criteria is the current interpretation of judicial precedent. The goal of these six criteria is just administration of justice governing all proceedings.

Counterclaims are very rare in treaty arbitration. According to UNCTAD, there have been over 800 treaty-based investor-state arbitrations to date, but unlike commercial arbitration and litigation, where a respondent is usually entitled to raise a counterclaim, the issue of counterclaims in treaty-based investment arbitration is problematic, or at least challenging, for arbitrators. Host State counterclaims in investment treaty arbitration are rarely raised and never successful, to the extent that one commentator has described their use as "thirty years of failure". This is mainly due to the nature of treaty arbitration, which operates as a triangular system where home and host States enter into an IIA, and investor benefits from the provisions of that IIA. This system often leads to an asymmetry of procedural rights, where only an investor can sue a host state, but not vice versa. This asymmetry in turn often leads to the deprivation of the right to bring counterclaims against investors. Nevertheless, counterclaims have an important role to play in treaty arbitration. While state counterclaims are permitted in principle under the ICSID Convention and the UNCITRAL Arbitration Rules, meeting the jurisdictional and admissibility requirements has proved more complex. This paper examines several key treaty provisions to identify those treaties that are more or less likely to extend a tribunal's jurisdiction “ratione materiae” over state counterclaims. The paper then examines the requisite connection that must exist between a counterclaim and the principal claim. A survey of international jurisprudence supports the paper's conclusion that recent treaty tribunal decisions have taken an unjustifiably narrow and often inconsistent approach to the requisite connection, to the extent that it may be virtually impossible for states to assert counterclaims under the current formulation. This paper proposes an alternative approach. This research examines the obstacles host states face in asserting counterclaims in investment treaty arbitration and critiques the reasoning of tribunals that have refused to hear state counterclaims. To this end, the paper proceeds in three substantive parts: it defines counterclaims, explains the overarching purpose of international investment law and arbitration, and promotes the potential value that a more permissive approach to host-state counterclaims could bring to the international investment regime. The paper agrees that investment tribunals should undertake the factual and legal assessment of the requisite nexus. However, in contrast to current practice, this paper recommends that legal nexus should be satisfied if a counterclaim relates to the same investment as the main claim, rather than insisting on symmetry in the legal instruments underlying the claims. This approach is likely to be more consistent with the jurisdiction of the tribunal as reflected in the relevant bilateral investment treaty. Crucially, this alternative approach also leaves open the possibility for state counterclaims to be based on the general domestic law of the host state. A greater role for host state counterclaims in investment treaty arbitration has the potential to save host states and foreign investors the time and expense of protracted battles in different fora over related disputes. Even in the same form, giving both parties the means to go on the offensive, rather than reserving this right to investors, may make states more willing to arbitrate and deter foreign investors from bringing weak claims. Despite these advantages, host state counterclaims are rarely brought and never successful. The first barrier is jurisdiction. Investment treaties make a standing offer to foreign investors which, once accepted, results in an arbitration agreement. This agreement determines the jurisdiction of the tribunal. The definition of the scope of disputes that the parties have agreed to submit to arbitration is of paramount importance. It will be easier for host states to assert counterclaims if the tribunal's jurisdiction is broad "ratione materiae", whether it is general, referring to "all disputes", or delineates several legal sources, such as authorizations and agreements. resolution clauses may limit the scope of the dispute to host state obligations or to the exclusive application of international law and/or the BIT. Other subsidiary provisions of the BIT may also help to limit the scope of the dispute. It will be easier for host states to assert counterclaims if they have locus standi or if the treaty explicitly directs the tribunal to apply the host state's general domestic law - but neither is determinative. The second obstacle is the requisite connection. A survey of international jurisprudence shows a general tendency to treat the requisite connection as a matter of both fact and law. The ICJ has adopted a flexible approach to the issue, treating both fact and law as relevant but neither as determinative. The Iran/US Claims Tribunal and treaty-based arbitral tribunals have taken a stricter approach, insisting on the symmetry of the legal instruments underlying the counterclaim and the claim. While a strict approach to legal symmetry may make sense in a commercial context, it does not apply to treaty-based arbitration because host states cannot assert counterclaims under the BIT. Nothing in the BIT test suggests that such a strict requirement is necessary. Moreover, tribunal practice suggests that counterclaims based on domestic law are prima facie inadmissible. The conclusion is that it would be virtually impossible for States to assert a counterclaim under the current formulation of the requisite connection test. Practice shows that counterclaims are in principle admissible in contract arbitration. However, their admissibility depends on certain factors: (1) the counterclaims must fall under the consent of the disputing parties (state and investor); and (2) they must be (closely) related to the main claim.

Arbitration as an alternative to state courts will succeed in fairly resolving disputes if it can remove the obstacles to hearings and guarantee the equal treatment of the parties. In litigations, judicial assistances (legal aids) such as insolvency proceedings come to the help of the impecunious party so that the economic obstacles do not lead to the violation of basic and fundamental rights such as access to justice and defense. while such assistances (legal aid) can be objectionable in arbitration, arbitrators begin looking in to the case only after receiving a fee sometimes considerable in amount. Arbitration institutions also have strict regulations in this regard. The status of the party who has to file a counterclaim, without being able to pay the relevant fee, is not clear. On the other hand, if the party cannot file the counterclaim, the arbitration award may be annulled due to the violation of a fundamental right such as access to justice...