Pakistan has agreed to return the tail of a U.S. helicopter that was damaged during the raid that brought an end to the terror leader Osama bin Laden earlier this month. As US Senator John Kerry says, the move will be instrumental in improving the ties between the two countries. But why is it so crucial for the US to get the chopper debris back?

According to ABC news report last week, Pakistani officials are interested in studying the remains of the helicopter and they suggested that the Chinese are interested as well, which raised the eyebrow of the US officials. The US demanded immediate return of the damaged helicopter as it doesn't want its sensitive military technology ending up in the hands of China, Pakistan's ally.

Former White House counter-terrorism advisor and ABC News consultant Richard Clarke said that the potential technological advancements gleaned from the bird (the chopper) could be a much appreciated gift to the Chinese. Because Pakistan gets access to Chinese missile technology and other advanced systems, Islamabad is always looking for ways to give China something in return, Clarke added. However, officials at the US Department of Defense declined to comment on the ABC report.

During the May 1 raid in Abbottabad, the helicopter, one of the four used in the operation, suffered a crash. Although the US special forces attempted to destroy it before the leave, the tail section remained intact, which was later recovered by the Pakistanis.

The crash of the helicopter is a major problem for the Navy SEALs who killed bin Laden. Numerous aviation experts said that the photographs of the wreckage of the chopper revealed several telltale signs of stealth technology. Had this particular helicopter not crashed, we still would have no idea of its existence, said Gareth Jennings, the aviation desk editor for Jane's Defence Weekly.

Although, in his remark on Monday, Kerry gave importance on both the countries finding a way to mend their frayed relationship in the wake of the attack, it's quite obvious that the US killing of Osama bin Laden has hurt Islamabad's ties with Washington. With Gilani's visit to Beijing starting on Tuesday, the entire tale has taken an interesting twist amid US rift.