WASHINGTON—Leaders of the world’s largest military alliance will arrive in the nation’s capital this week to carve out a strategy for countering a widening suite of crises in Europe, the Middle East, and the Indo-Pacific.

The annual NATO summit in Washington marks the 75th anniversary of the defensive alliance and comes at a time of heightened geopolitical tension throughout the world.

Foremost among the alliance’s concerns is Russia’s continuing war in Ukraine, which has at times threatened to spill over international lines and draw in the NATO powers that have delivered hundreds of billions of dollars worth of humanitarian and military assistance to Kyiv’s war effort.

Russian President Vladimir Putin has referred to the war as a “special military operation,” the stated objectives of which were to demilitarize Ukraine and prevent the nation from joining NATO.

Mr. Putin reaffirmed the latter part of that goal last month, saying that he would accept a cease-fire if Ukraine surrendered its eastern provinces and signed an agreement that it would never join NATO.

The war has served as a catalyst for reinvigorating the once-languishing alliance.

Russian aggression against Ukraine has instead resulted in the accession of two new NATO members, Sweden and Finland, and has driven a massive increase in defense spending among the alliance’s now 32 member states.

Speaking during a call with media outlets last week, a senior Biden administration official said that the number of NATO nations spending at least 2 percent of their gross domestic product on defense had risen from nine to 23 since 2020.

“That direction of travel is significant,” the official said. “To put a dollar figure on it, just since 2020, NATO collectively has spent an additional $180 billion on a yearly basis.”

To that end, a key goal of the summit this week is to demonstrate a united resolve against Russian efforts to permanently separate Ukraine from NATO.

The official said that NATO leaders would unveil a new military command and a suite of other deliverables to help prepare Ukraine to assume the responsibilities of NATO membership “on day one.”

That effort, referred to as Ukraine’s “bridge to membership,” will be further augmented by 20 to 30 bilateral security agreements between individual NATO member states and Ukraine.

However, Ukraine currently has no realistic pathway to membership in the alliance despite the show of solidarity.

This is because Ukraine would need to garner unanimous support from all NATO members, including Hungary and Turkey, which are unlikely to prove amenable to actions that Russia would perceive as overly provocative.

Also looming in the background is the threat posed by the Chinese Communist Party (CCP), which the alliance has increasingly poised itself to counter over the past two years.

Although all NATO member states are located in Europe and North America, the alliance included communist China as a key security concern in its official strategic guidance document back in 2022.

A key concern among NATO officials is the CCP’s continuing economic and technological support for Russia, with NATO Secretary-General Jens Stoltenberg going as far as to say that “China is the main supporter of Russia’s war effort in Europe.”

Likewise, Mr. Stoltenberg has linked Russia’s war in Ukraine to the CCP’s aspiration of forcibly uniting democratic Taiwan with mainland China and said that a Russian victory in the West would lead to Chinese aggression in the East.

“If you are afraid of Chinese aggression in the South China Sea or Taiwan, then you should be very concerned about Ukraine,” Mr. Stoltenberg said during a virtual address to the Wilson Center think tank on June 17.

Closer to home, NATO is still reeling from the revelation that a CCP-backed cyber campaign successfully placed malware on tens of thousands of systems, including in Western defense organizations.

Dutch intelligence revealed last month that the campaign, dubbed Coathanger, compromised 20,000 systems across dozens of Western governments, international organizations, and a large number of companies within the defense industry.

The scope of that discovery suggests that the campaign sought to gain persistent access to the defense industries of Western nations, but it remains unclear whether all of the victims were located in NATO nations or shared some other connection.

One more point of interest is sure to be Israel’s war against the Hamas terrorist group in Gaza, which has also at times threatened to spiral into a much larger regional conflict.

NATO vowed to support Israel following Hamas’s Oct. 7, 2023, terror attack on Israel, in which about 1,200 people, mostly civilians, were killed and more than 250 hostages were taken.

However, that support is a contentious point for world leaders, who have struggled at times to balance the desire to arm Israel and the desire to preserve civilian life in Gaza.

The United States has passed legislation to provide Israel with more than $13 billion in security assistance since October 2023.

However, the Biden administration has paused one shipment of 2,000-pound bombs over concerns that the weapons would be used in densely populated areas where refugees have been forced to flee.

As such, how the alliance responds to the ongoing quest for a cease-fire with Hamas could have broad implications for U.S. strategy in the Middle East.

A final focal point will be President Joe Biden himself, who has come under fire from a small group of House Democrats who believe that the president’s performance during the first presidential debate with former President Donald Trump demonstrated that he is unfit to continue his candidacy for a second term in office.

The outcry has prompted the president to reaffirm that he is staying in the race and that he believes that he is the Democrats’ best option to secure victory at the polls in November.

Several unscripted moments throughout the week, including photo ops and state dinners with fellow world leaders, will give the president the chance to prove whether he has the ability to hold the office in the eyes of his party, the U.S. public, and the rest of the world.