Now you’ve done it—cemented a relationship to design the first tower on the former World Trade Center site. We saw the reluctant look in your eyes as you accepted the inevitable and embraced in the photo-op; we saw the wary resolve and the lingering questions of what lay ahead for you both. We could tell it in your smiles: A forced marriage is never an easy one.

You need to know that every architect in this country—all 100,000 of us—stand behind you. Most architects worldwide join in wishing you two, and the groups that you represent, well. However, in the same breath, we’re united in saying, “Don’t mess this up.”

You both will face skepticism, including cynicism from architects and the general public, that the dynamic forged in the original selection process has been subverted. Remember what has already happened: the hours of agonizing conceptual design, the hundreds of thousands of dollars spent by the LMDC and other teams of architects, the white-hot glare of the klieg lights focused on a choice. This choice. Despite the gaffes along the way, and the public repudiation of interim plans, Libeskind’s plan emerged relatively unscathed.

With good reason. Daniel Libeskind captured something beyond mere building in his drawings. His first plans, presented at the Winter Garden in December 2002, caught the moment with a vertiginous edge, presenting a gritty, angular view of today’s New York. Those first renderings, looming up from the Manhattan schist to asymmetrical high-rises, said something authentic about the people and the place with a dizzy energy. We recognized ourselves in those plans; you got it right.

Outside pressure and events have already affected the outcome. No one can deny that the PATH station had to return to service, but subsequent requirements have reduced the plaza’s depth from approximately 70 to 30 feet; the Gardens of the World, which originally seemed more conceptual than actual, evolved into an open tower. Further changes will be inevitable and may prove beneficial as the plans mature. However, any decisions that smack of expediency and threaten to compromise the force of the original must be rejected. That advice goes for the whole team, for your client, and for each of you individually.

David Childs, you have engaged complex programs before, though never with this critical attention. The stewardship of such a prime site, if managed properly, can gain you immeasurable international admiration, orchestrating the Libeskind scheme through the rough days ahead. Cave in too quickly, allowing this site to become a commodified real estate deal, or lend too heavy a hand to work that has already lodged in the public consciousness, and you will have failed in all our eyes. If you keep the Libeskind vision intact—not allowing the client or political wrangling to blunt the edges—you may find greatness within your grasp.

Daniel Libeskind, do not surrender or weaken the ideas you have already forged. When you have presented your intentions for New York and the WTC site, those present have risen to their feet and applauded. You’ve been forced into a compromise marriage; keep December’s triumph in mind as you proceed through the coming months.

Both of you will be tested. Your client, the developer Larry Silverstein, controls the purse strings. The Port Authority, a relentlessly pragmatic institution, owns the land. The Governor of the State of New York holds the political cards. But make no mistake. Ultimately, your client is the public, bound to this place and this process by an ethical trust that you both share. All of your fellow architects support you in your work as you begin the translation of a strong idea from two to three dimensions.

Here’s your charge from all of us: Make it sing.