OTTAWA – Prime Minister Justin Trudeau will be in Brussels on Wednesday for a two-day summit of the North Atlantic Treaty Organization (NATO).

There, he and representatives of the 28 other members of the military and political alliance are set to discuss major national security issues such as cybersecurity, Russian aggression, and terrorism.

As Trudeau deliberates and dines with other world leaders, here are three big issues facing him, and the Canadian delegation, at the summit:

1) Defence spending pressures

U.S. President Donald Trump’s letter to Trudeau, and other nations has set the tone going in to the summit. In the letter, according to a Canadian Press report, Trump cited "growing frustration" over Canada and other allied countries not meeting their defence spending targets.

As of June 2017, six of the 29 NATO countries (U.S., Greece, U.K., Estonia, Poland, and Romania) were projected to meet the collective agreement to spend 2 per cent of their GDP on defence.

While the federal government has pledged to increase what it spends on the military, the June 2017 report on the defence policy review, titled "Strong, Secure, Engaged," makes it clear that come 2024—the year set out by NATO to meet the two per cent target—Canada will not be spending more than 1.4 per cent of its GDP on defence. Canada is currently middle-of-the-NATO-pack on this, with 14 nations spending more than Canada’s 1.29 per cent of GDP in 2017, and thirteen countries spending less.

View a larger version of the chart here

It is expected Trudeau will look to counter this pressure to spend more by demonstrating through his visit to the 455 Canadian troops in Latvia, and newly announced extension of the mission, that Canada punches above its weight when it comes to operational commitments.

"I think it's going to be tense because I don't really have any confidence that the government's message is going to resonate with the president of the United States at all," Canadian Global Affairs Institute’s David Perry told CTV News.

Ahead of the summit, Conservative MP James Bezan released a statement criticizing the federal liberals for not making "meaningful progress" towards reaching the spending target and calling on the government to do so immediately. In the statement, Bezan pledged that if the Conservatives formed government they would "ensure that our NATO commitments are met."

Though, the previous Conservative government under then-Prime Minister Stephen Harper also faced NATO pressure to spend more on the Canadian military.

Trudeau won't be the only NATO leader attempting this diplomatic dance with Trump at NATO. But it’s also possible that Trump might not be alone at the other side of the table, with other nations who are meeting their commitment adding to the pressure to pay up.

"I think there's a fair amount at stake. He's, first of all, got to find a way to escape a confrontation with President Trump and possibly not only with him but with some of the other allies who are ponying up more resources for the alliance," said Conference of Defence Associations Institute Fellow Col.-Ret Charles Davies.

"It's a very difficult balancing act that Canadian politicians, Canadian leaders have been making for decades; 'How much do we spend? Is it enough? Is it enough to keep the Americans reasonably happy? Is it enough to keep our other allies reasonably happy?' It's a political calculation that every prime minister has made and probably will continue to make," Davies told CTV News.

2) Canada-U.S. relations

Dovetailing with Canada's efforts to avoid a conflict with Trump’s over spending, will be navigating the considerably fractured bilateral relations between the two countries. This summit will be the first time Trudeau and Trump are to be face-to-face since Canada levelled retaliatory tariffs on U.S. goods, over its steel and aluminum tariffs on Canada.

This week, Trump connected the two issues over a pair of tweets, directed at the European Union, though the same argument could be applied to Canada, if Trump so desired.

Doubling down on his defence spending message, Trump stated that the U.S. spending more than others is "not fair nor is it acceptable," and that "on top of this" the EU has a trade surplus with the U.S.

It is yet to be seen how, or if Trump brings up the tariffs at the NATO summit. Though, there's already been indications that the exchange of tariffs is having a financial impact on American, and Canadian industries.

The values of 2017 imports from U.S. for some of the products targeted by Canada's preliminary tariffs include:

Much like the defence spending pressures, this dynamic of tariff tension will not be exclusive to Canada, as the U.S. has taken similar measures against other European member countries.

This has NATO and domestic American political watchers curious what Trump’s approach will be at the summit.

"Particularly coming out of the G7 summit, and as Trump heads to Russia and the UK… It's important to look at how he’s behaving, how he’s interacting with these other leaders because I think that will have a large impact on not only the success of the alliance going forward, but how Trump views bilateral relations with any and all of these countries," Global Fellow at the Wilson Center's Kennan Institute Nina Jankowicz told CTVNews.ca.

According to a Nanos Research survey Trudeau's approach to the trade dispute with the U.S. has been received majority support domestically.

The report, commissioned by CTV News and The Globe and Mail found that seven in 10 Canadians (or 71 per cent) approve or somewhat approve of Trudeau’s handing of the trade relationship with Trump. About one in four (26 per cent) disapprove or somewhat disapprove of Trudeau’s approach.

3) Looming cyber threats

In June, NATO Secretary General Jens Stoltenberg cautioned a London audience that the world is facing "the most unpredictable security environment in a generation" citing Russian aggression, cyberattacks, and terrorism.

During his remarks Stoltenberg—who will host this week’s summit— focused on the future of the trans-Atlantic partnership. NATO watchers say the alliance’s position on cyber threats will be one of the bigger, overarching questions at the summit.

While NATO's primary focus when it comes to cyber threats has been from a defence perspective, and less so that of the impact on democratic governance, Jankowicz said with some NATO members such as Turkey and Hungary having experienced "democratic backsliding," without any consequence from the alliance, it's possible that this position will be revisited.

"I think NATO is kind-of searching for its 21st century rebranding in some ways, and disinformation and cyber defence are an arm of that," she said.

Given this, and the Trump meeting with Russian President Vladmir Putin on July 16, it’s possible this issue could occupy some space in Trudeau’s brain over the two-day gathering.

The next federal election in Canada is 15 months away. Nomination meetings are already underway for the 2019 Trudeau team of candidates, and domestic agencies have warned that Canada is not immune to the threat of foreign interference in the democratic process, with little yet to be done to protect against this by the government.

In fact, Canadian troops in Latvia have been the subject of online Russian propaganda, as has Foreign Affairs Minister Chrystia Freeland, who has been targeted by "Russian propagandists," as Trudeau put it, with fake news about her family.

Russia was certainly on Trudeau's mind on Tuesday in Riga, where he spoke with reporters after meeting Latvian Prime Minister Maris Kucinskis.

"Russia continues to be a country that is looking to disrupt and destabilize the global rules-based order, and basically cause problems on the international stage," Trudeau said.

"We will continue to engage with Russia in constructive ways as much as we can to highlight that it’s our expectations that they would begin to play a more positive role on the global stage, but at this point I have to say we continue to have a difficult relationship with Russia because their actions are simply not consistent with what we as a democracy… it’s not what we could accept."

With files from The Canadian Press and The Associated Press