LONDON — Theresa May’s sure-footed start to foreign relations has impressed world leaders. Diplomats in Paris and Berlin speak of a “serious” and “astute” politician that they can deal with.

But back at home a quiet unease is emerging.

As she heads to her first international summit as prime minister —the G20 in China this weekend — May’s foreign policy remains unknown, even to senior members of her government.

“There are lots of questions but very few answers,” one senior Tory said. Others are less circumspect. Asked about her world view, a long-term former cabinet colleague replied: “Absolutely no idea.”

May’s foreign policy silence is causing murmurings of disquiet. Privately, ministers voice unease about the influence of her advisers, particularly Chief of Staff Nick Timothy.

As one senior Conservative source put it: “She should not just look for solutions from those who sit closest to her desk.”

Another well-connected Tory said: “I’ve literally no idea on foreign policy. It’s very difficult to say who she’s close to or what she thinks. Most stuff seems fairly traceable to Nick [Timothy].”

May’s early suspicions about China have raised eyebrows in Westminster and abroad; she is defiantly lukewarm toward Europe and notably unattached to the U.S. On Russia, Ukraine and the Middle East, May’s position is unknown.

The assumption in Berlin is that the U.K. will continue to lose international influence.

Foreign leaders are not overly concerned. In European capitals, Britain’s international retreat is considered “a given,” according to a number of well-connected diplomatic sources.

One source close to German Chancellor Angela Merkel said the U.K.’s foreign policy now amounted solely to Brexit. The assumption in Berlin is that the U.K. will continue to lose international influence, with its nuclear arsenal and United Nations Security Council seat its “last vestiges of power.”

Those close to the German chancellor see the appointment of Boris Johnson as foreign secretary as evidence May doesn’t really care much about foreign policy. French anger over Johnson’s promotion was acute, but there is now a feeling in Paris that he has been silenced.

Jonathan Eyal, assistant director at the respected foreign affairs think tank RUSI, said European concerns about the Brexit triumvirate of Johnson, David Davis and Liam Fox were serious and damaging.

“There is now a rather dangerous myth in Europe that if they need a serious decision, they have to talk to her [May] and not to her ministers. All of her ministers are deemed to be lightweight.”

A step up from Cameron

Eyal said that May had impressed in her early visits to Berlin and Paris. “They were struck by how serious she is.” The contrast with David Cameron, who often tried to “wing it,” has been noted.

“She is meticulous. When she has meetings with foreign leaders she is well prepared,” Eyal said. “In Paris they expected a very tense meeting, but it was all very low key, she kept her voice down. That is a very important departure from the previous prime minister. But this is all the calm before the storm. In Europe she still constitutes a leader on borrowed time.”

A senior source in Berlin said it “goes without saying” that because of her cabinet appointments May is considered the only one “worth dealing with.”

Merkel believes the British prime minister will be too busy dealing with Brexit to devote much time to other issues. The German chancellor is, however, very keen to preserve a good relationship with the U.K., especially on trade. The initial impression in Berlin is that May is someone they can negotiate with in a fairly sober manner.

Berlin also believes Britain’s retrenchment was already underway before May took over. In particular on Russia and the Ukraine, London was seen as “invisible.”

French diplomats harbor deeply-held historical concerns that the U.K will return to “the centuries-old Foreign Office game of dividing Europeans.” Cynics in Paris, though, accept Britain has never really stopped playing that game, even in the EU.

French fears

There is a more serious concern in Paris about British military retreat — in particular, May’s willingness to engage forces abroad.

A close study of May’s record suggests the French are right to be concerned.

In the only notable foreign policy speech of her career, in 2011, May broke with the U.K. government line to question the prospects of the Arab Spring.

The May worldview: Cautious, pragmatic and skeptical about liberal interventionism.

As other ministers hailed the “exciting” revolutions, May said: “Change for the better is not inevitable … There is a chance that the Arab Spring does not bloom; that new repressive regimes replace old ones; that they give way to new and more dangerous regimes; or that terrorists gain the space and power that they lacked under the autocratic regimes of the past.”

Timothy, her closest adviser and chief of staff, hailed her “prescience” in a later blog post as he laid out the most detailed account of his foreign policy, attacking liberal interventionism. In it he said the “single, overriding lesson from Iraq” was that the U.K. needed to “rediscover the principles of a traditional, realist, conservative foreign policy.”

He added: “Value stability. Respect sovereignty. Do not make foreign policy part of an ideological crusade. Do not try to recreate the world in your own image. Do not, however much you might disapprove of a dictator’s abuse of human rights, use that as a pretext for regime change. Always act on the basis of the national interest. Above all, understand the risk involved when things change in complex and volatile states.”

In Timothy’s writings and in May’s cautious, pragmatic record in government the bones of her foreign policy can be seen.

A Number 10 source said May was, at heart, “a pragmatist.” “She does what is in the national interest.” May will not be making any Cameron-style comments about Donald Trump, the source added.

Worried world

Foreign Affairs Select Committee chairman Crispin Blunt said May had a “toughness” Cameron did not have when it came to resisting the “emotional pull” of foreign interventions. But he added that she would still “go on the same journey every a prime minister does” eventually being “sucked into international affairs.”

Blunt also insisted Europe had it wrong if they thought Brexit constituted a retreat. “For the next two or three years we re-establish our role in the world. The three Brexit ministers have a clear understanding this is history, I know. They have got these jobs at a very profound moment and have to make it work. This is not politics as usual over the next two and a half years.

“The triumvirate working for Theresa is about as good a core team to do Brexit as is available in U.K. politics. I accept that’s not how they are seen, but that’s how they are.”

Blunt admitted, however, that he was “very worried” about the capacity of the Foreign Office to cope with its new responsibilities. “We’ve got to raise our diplomatic game. The world is looking at us.”

May now has a job convincing the world — and her domestic critics — that Britain has not given up.

Pierre Briançon and Nicholas Vinocur in Paris and Matthew Karnitschnig in Berlin contributed to this article.