We know who is piloting the American ship of state through the turbulent waters of global diplomacy. We just don’t know where it is going.

Neither do the leaders of traditional U.S. allies, including Canada; nor America’s foes, including Iran; nor those countries that, in the Donald Trump years, bounce between being rivals and friends, including North Korea.

This has been apparent since the moment U.S. President Donald Trump took the oath of office, but it has never been so clear as it has been in recent days, when the United States has failed to clarify its findings, its interests or its inclinations in the wake of a series of attacks against Saudi Arabia that may have come from, or been prompted by, Iran.

Story continues below advertisement

The President, whose remarks about his domestic rivals never lack clarity (or restraint), has practised a curious opacity (and deliberate restraint) when it comes to contretemps such as the escalating tensions in the Middle East. Senator Elizabeth Warren, the Massachusetts Democrat running for president, knows where she stands with Mr. Trump. Iranian President Hassan Rouhani does not.

Indeed, Team Trump often speaks with multiple voices. Just this week, the President used one of his trademark phrases with Iran, asserting (as he once did with North Korea’s Kim Jong-un) that U.S. armed forces were ‘’locked and loaded,’’ which is to say that they were ready for powerful, direct military action. Then he made clear that military action was not really an option. But that was not the end of it. Mr. Trump later said the decision to undertake a strike against Iran rested not so much with the United States as it did with the Saudi leadership. He spoke of war as the ‘’ultimate option.’’ He weighed a welcome for Iran’s President – and considered sanctions. At the same time, Secretary of State Mike Pompeo said that Iran had conducted an “act of war."

As the U.S. President seemed to think out loud, America’s allies matched Mr. Trump ambiguity for ambiguity.

On the one hand, there are indications that Mr. Trump is taking a page from two of his most reviled families, the Clintons and Bushes, who both employed the phrase ‘’coalition of the willing’’ as they sought allies while they contemplated military action. On Thursday, during a stopover in the Middle East, Mr. Pompeo said the “coalition” Washington was seeking to build is aimed at a “peaceful resolution” to the crisis. But in this case, Europe and Canada don’t seem very willing to join in any American undertaking, especially since it remains unclear whether the United States will undertake anything at all.

In Towards The Flame, a magisterial 2016 account of the end of czarist Russia, British historian Dominic Lieven spoke of the diplomatic world that grew out of the alliance system that developed in Europe from 1879 to 1894, producing a brisk and efficient summary of how foreign relations are customarily conducted:

‘’In international relations, it is vital to define key interests, make clear that other powers understand the definition, and show to all that one has the will and the available force to defend those interests if the need arrives.’’

Even some of the President’s most ardent allies believe the Trump team has failed almost every element of the Lieven test.

Story continues below advertisement

Indeed, in international relations, he has questioned the value of long-term American alliances, including NATO; criticized long-time American allies, including Canada; questioned the value of international institutions, including the United Nations; and derided the work of his own intelligence agencies, including the CIA.

Previous presidents have done at most one of those. None has dared do all four. Mr. Trump has, and he combines it with a trade war with China, the rising power of the era.

The situation is reminiscent of what British opposition leader Benjamin Disraeli said after the Franco-Prussian war ended in 1871:

“Not a single principle in the management of our foreign affairs, accepted by all statesmen for guidance … any longer exists. There is not a diplomatic tradition that has not been swept away. You have a new world, new influences at work, new and unknown dangers and objects with which to cope.”

At the same time, with a narrow route to re-election in 2020, the President has widened the divisions in his own party, splitting the GOP domestically on the importance of fiscal austerity and balanced budgets and in national security on the question of asserting American power abroad. In the latter realm, neo-conservatives with an interventionist instinct are battling those who prefer caution and diplomacy with new fervour, creating divisions perhaps even wider than those under the George W. Bush administration more than a decade ago.

‘’There is a segment of the Republican Party that is itching for a war with Iran,’’ said David Azerrad, director of the Simon Center for Principles and Politics at the Heritage Foundation, a conservative think tank in Washington. ‘’The Trump wing of the Republican Party has so far prevailed in slowing things down. No one here thinks that Iran has a good regime, but we have had two long, drawn-out wars of regime change recently and they have not worked out well.’’