The road to the House resolution offers two lessons that go beyond the United States and Turkey.

First, as a baseline rule, for the sake of overall American credibility and for that of our diplomats, Washington officials must be empowered to tell the truth.

Over many years, because of the fear of alienating Turkey, diplomats have been told to avoid mentioning the well-documented genocide. In 2005, when John Evans, the American ambassador to Armenia, said that “the Armenian genocide was the first genocide of the 20th century,” he was recalled and forced into early retirement. Stating the truth was seen as an act of insubordination.

When I became ambassador to the United Nations in 2013, I worried that I would be asked about the Armenian genocide and that when I affirmed the historical facts, I could cause a diplomatic rupture.

Second, when bullies feel their tactics are working, they generally bully more — a lesson worth bearing in mind in responding to threats from China and Saudi Arabia. The Turkish government devotes millions of dollars annually to lobbying American officials and lawmakers: more than $12 million during the Obama administration, and almost as much during the first two years of the Trump presidency. Turkish officials have threatened to respond to genocide recognition by suspending lucrative financial ties with American companies, reducing security cooperation and even preventing resupply of our troops in Iraq.

On Friday, the Turkish ambassador warned that passage of the “biased” House resolution would “poison” American-Turkish relations, and implied that it would jeopardize Turkish investment in the United States which provides jobs for a “considerable number of American citizens.”

It is easy to understand why any commander in chief would be leery of damaging ties with Turkey, an important ally in a turbulent neighborhood. But Turkey has far more to lose than the United States in the relationship. The United States helped build up Turkey’s military, brought it into NATO and led the coalition that defeated the Islamic State, which carried out dozens of attacks on Turkish soil. Over the past five years, American companies have invested some $20 billion in Turkey.

If Mr. Erdogan turns further away from a relationship that has been immensely beneficial for Turkey in favor of deepening ties with Russia or China, it will not be because the House voted to recognize the Armenian genocide. It will be because his own repressive tactics are coming to resemble those of the Russian and Chinese leaders.