Many attorneys avoid being civil or diplomatic in their cases, as they want to zealously advocate for their client, but diplomacy can be an effective form of advocacy. While diplomacy is not a substitute for litigation skills, it does carry the following advantages:
Diplomacy Doesn’t Change The Merits: As discussed in Weighing Legal Arguments, cases should be evaluated on their merits. Taking a diplomatic approach to the case will not change the merits of the case.
Diplomacy Increases Credibility: As discussed in the Means Of Persuasion, credibility is one of the most important means of persuasion. Being diplomatic will increase an attorney’s credibility with opposing counsel and the judge.
Finding Common Ground: It will be easier to find common ground if you take a diplomatic approach to your case. This is especially true in criminal cases, where the prosecution is not necessary looking for the biggest sentence they can get, and are more likely to give deference to attorneys who are fair with them.
Reduces Risk & Effort: In general attorneys like to reduce the risk of litigation, and avoid performing any unnecessary work. By discussing the issues in good faith an attorney can reduce the uncertainty and risk in a case by narrowing the issues (if there are less issues being litigated there is less risk). They can also decrease the work by avoiding unnecessary discovery, motions, and depositions that are not related to the issues currently being litigated.
Pick Better Issues To Litigate: By discussing the case in good faith you probably have a better understanding of the issues in dispute, and are in a better position to Pick Your Battles.
CONCLUSION
Diplomacy is a long term strategy to litigation just as much as it is a short term strategy. Attorneys often run into each other after the case is over (this is especially true in criminal law). In the legal world it's better to not burn any bridges. You never know who you will need help from tomorrow.
Sometimes opposing counsel's strategy is to just pound on you as hard as he can. In these situations there is no point in taking a diplomatic approach to the case, and you should deal with opposing counsel at arms length.