Has the time come for Andy Reid and the Eagles to part ways? (Bill Kostroun/AP)

When the partnership has been successful, the most successful one in either party’s history, no one wants to call it quits, even if it’s for the best. Memories hold us back; nostalgia blinds us to the grim reality that it’s just not working while somehow not revealing that the best days are all behind us.

Andy Reid’s relationship with the Philadelphia Eagles will reach its 12-year anniversary in January, and it’s hard to argue that he isn’t the greatest coach the team has ever had. But is that enough to keep this partnership going?

When the Andy and the Birds hooked up in 1999, neither had much to brag about. They were both coming off of bad relationships. They had their quirks, but it somehow seemed to work, despite outcries from the local media.

The courtship was quick and memorable, and marked by the maligned arrival of Donovan McNabb. But both the Eagles and their new coach believed in each other and that trust and patience was rewarded. Together they grew stronger — a faltering franchise reborn, an unknown coach proven.

In 2001, Reid was given shared control of the team when he was named Executive Vice President of Football Operations. They built a new home called Lincoln Financial and moved into the greatest era of Eagles history. They soared high on shared dreams, winning four division championships in a row. They were celebrated — the envy of the NFL. They reached the Super Bowl and were three points from the title that a championship-starved town had chased for two decades. And then they came up short.

Did the team peak in 2004? Were they ever the same after T.O.? Can they ever be better than second best?

But Reid and the Eagles stuck together when things got rough. They stood side by side in the face of criticism. They ignored their flaws out of loyalty. They worked together to reclaim their former passion. When things broke, they refused to acknowledge it. They adapted to adversity with grit, chewing gum and duct tape (read: Jeff Garcia) returning to the NFC Championship in 2008 only to blow it one more time.

Publicly they kept a unified front as what they built began sinking. It’s easy to smile, say the right things and stand on past success in front of flashbulbs. Behind the closed doors of a seemingly peaceful front office, critical voices can grow deafening. In a league dubbed Not For Long, past success works like a lead vest, not a life preserver.

With each passing season the strain felt more apparent, the missteps more irrevocable. That only made the performance harder as the critics’ voices grew. Reid’s relationship with the Eagles was more about denial than mutual growth. The excuses and the rhetoric grew thin, like a bad play when the actors no longer care. With a 1-3 start to 2011, the writing may be on the wall.

The Eagles and Andy Reid are facing the biggest test in the history their relationship. There are painful questions that neither side wants to answer: How long can you continue believing when your closest supporters think you’d be better off apart? When is it time to let go of an unrealized dream? How long can you keep telling yourself that what doesn’t kill you can only make you stronger?

For Reid and the Eagles the answer to all of those questions is January 1, 2012. Without the miracle reconciliation of a playoff berth and perhaps a Hollywood ending in Indianapolis, the “Dream Team” will get a resounding wakeup call — they had something special and now it’s time to part ways.