Donald J. Trump’s campaign for the presidency was unconventional.

His transition into the office he has won is even more so.

We often hear it said that “We have only president at a time.” Trump, though, is using his Twitter account to suggest something that borders on the otherwise.

The United States this past week abstained on a United Nations Security Council vote that condemns Israel over its settlement building on the West Bank; U.S. policy for years has been to veto such a resolution. Thus, the Obama administration broke with longstanding U.S. policy.

Then in comes Trump to tweet that the United States was wrong to abstain; that the U.N. is a “sad” organization.

The point here is that presidents-elect traditionally have let the current president conduct foreign policy. They wait relatively quietly while they prepare to take office; then they are free to change whatever policy they wish.

Trump isn’t waiting for Inauguration Day. He’s blasting the daylights out of President Obama whenever he sees fit using his Twitter account.

My wish would be for the president-elect to hold his fire until he becomes the president. Americans actually do have just one president at a time.

Donald Trump’s time is coming on quickly. Until he takes the oath of office, he ought to keep his trap — and his Twitter account — quiet.