Earlier this week, Donald Trump put out a National Security Strategy that made no mention of climate change. This struck some observers as curious, given that many of his top generals — including Secretary of Defense James Mattis — have gone on the record stating that climate change is indeed a threat to national security.

The impact this omission will have on America’s actual security posture is likely to be muted. But the diplomatic impact could be profound.

The security community often refers to climate change as a “threat multiplier.” Stronger storms, rising seas, drought, famine, and the migration these events cause have the potential to enflame tensions around the world. Any number of climate-exacerbated natural disasters could ignite conflicts that require global attention or threaten the US’s security. One prominent example is the Syrian Civil War, which was in part triggered by an historically bad drought and has become one of the defining conflicts of the early 21st century.

Mattis and others in the Trump administration have also argued that efforts to make the US military more sustainable — such as outfitting naval vessels with solar panels — are good strategic moves, regardless of their potential to help save the planet.

So why did Trump’s National Security Strategy omit any mention of climate change? Obama’s 2015 document, the last published, used the term 13 times.

The omission can be at least partially chalked up to the fact that the National Security Strategy is a political document, not, despite its name, one that dictates military strategy. As Jamie McIntyre and Travis Tritten write for the Washington Examiner, the document Trump unveiled Monday “was written for him, not by him.”

The document was crafted by the staff of the National Security Council with the president’s sensibilities and public statements in mind. As David Titley, a retired rear admiral and the former COO of NOAA, told USA Today, “You try not to take the flaming hot poker iron and stick it in your boss’s eye.” The document mentions the need for “energy dominance” — a term favored by the administration — but contains only a vague commitment to “remain a global leader in reducing traditional pollution, as well as greenhouse gases, while expanding our economy.”

In practice, the document is likely to have little effect on US military operations. It does not prohibit the Department of Defense from continuing its work on climate and from taking climate change into consideration going forward. Far more important for dictating military strategy is the National Defense Authorization Act, which Trump signed into law earlier this month, and which included a large section on climate change, approved by both Republicans and Democrats in Congress.

Trump’s National Security Strategy omission of climate change will not be entirely without effect.

The one area where the document will likely matter is US diplomacy and foreign policy, where it could deepen the diplomatic damage done when the US announced its intention to pull out of the Paris Climate Agreement. The role of climate change in conversations around global security is an area in which world leaders have still been able to engage with the Trump administration, despite the president’s unyielding climate skepticism.

“It was the one space where our partners and allies might have still held out hope that the US would focus attention and maintain some leadership, whether at the UN Security Council or in other fora,” says Francisco Femia, director of the Washington, DC-based Center for Climate and Security. “To withdraw even from that space demonstrates to our partners and allies that we’re not serious at all about this issue.”

The signal that Trump’s National Security Strategy sends, Femia says, is that the US does not just disagree with its allies about how to go about cutting its greenhouse gas emissions — the disagreement is “also about the very nature of the problem of climate change.”

“On a very broad level, that’s a poor signal to send,” Femia says.

Such a shift could play into the narrative that the US is ceding climate leadership to China, a narrative that China — which has not always supported initiatives related to climate security at the UN — is happy to embrace.

The Trump administration has already sent a slew of mixed signals on climate by announcing its withdraw from the Paris Climate Agreement, but then sending State Department diplomats to climate talks. In Bonn this November, the diplomates in the US delegation behaved in much the same way they did under Obama. The picture was further complicated by the appearance of administration officials, who attempted (without much success, so far) to push fossil fuel interests at the climate talks.

The US could now cause similar confusion when it comes to issues surrounding climate change and security by saying one thing and then doing another. Despite Trump’s National Security Strategy, much of the US government will still likely engage on these issues — so long as the personnel doing the engaging know that word won’t get back to the White House.