As President Zelensky was making his way to Japan for this weekend’s meetings with leaders of the group of seven richest countries, the Ukrainian leader found himself in an awkward position Friday at Riyadh, sharing a summit room with Russia’s top Mideast ally, President Assad of Syria.

At Hiroshima, Japan, Mr. Zelensky will try to convince the G7 leaders that he needs more arms to win the war Moscow launched more than a year ago. The group has already announced a new set of sanctions on Moscow. More importantly, President Biden reportedly has changed his mind: He is now ready to approve the sale of F-16s to Ukraine and train its pilots on the advanced fighter jets. 

By a wide margin, America is Ukraine’s largest supporter in terms of funding and arms. Yet, Mr. Biden has long hesitated about timely delivery of offensive weapons. Howitzer artillery, M1 Abrams tanks, and now F-16s have been on Kyiv’s wishlist long before America has ended up delivering them. Washington argued that such arms are not really needed, are wrong for the Ukrainian terrain, or are too complex. 

The delay raised questions about Mr. Biden’s goals. Does America back Mr. Zelensky’s hope of dealing a decisive military blow to Russia by recovering all its occupied territory, including Crimea? As in Syria, Russia appears to be hoping for a stalemate with Ukraine, which of course could end in victory.  

Mr. Zelensky’s short visit at Riyadh on Friday may illustrate the difference between a protracted war and victory. Playing on the constant Arab plaint over the region’s colonial past, he told the kings, potentates, emirs, and dictators that “anyone who defends their native land against invasion and anyone who defends their country’s children from enslavement is on the path of justice.”

The listeners knew, of course, that he wasn’t referring to Palestinians fighting Zionists or Iraqis attempting to push out the American occupiers. He was talking about his own struggle against the Russian invader. Yet, what would the most notable guest at this year’s Arab League summit, the Butcher of Damascus, make of Mr. Zelensky’s speech? 

Mr. Assad has presided over a long civil war that killed more than half a million people and turned millions of others into refugees. Twelve years ago, that war earned him an expulsion from the Arab League. His Friday return, including a warm welcome from the host, the Saudi crown prince, sealed Mr. Assad’s war victory.

It also proved that rather than principles, as articulated by Mr. Zelensky, the region ultimately mostly appreciates the language of brute force. There are losers and winners, and the good guys will not necessarily come out on top. 

America and others were appalled by Mr. Assad’s brutal assault on his own people. Washington’s battle cry was, “Assad must go,” and President Obama drew a red line on the use of chemical weapons. Mideast leaders, who at that time still saw America as the region’s top power broker, shunned Mr. Assad. 

That ended when Mr. Obama’s red line essentially turned into a green light. Mr. Putin saw an opening and entered the Syrian war on Mr. Assad’s behalf, alongside another anti-American player, the Islamic Republic of Iran. The Putin-Assad-Khamenei axis eventually won the war.

Washington wanted to reduce America’s Mideast footprint and endlessly talked about diverting from the region’s fossil fuels. No wonder the core membership of the Arab League started looking elsewhere. Now, even as Mr. Biden endlessly preaches human rights, Arabs embrace the once-shunned Mr. Assad. 

That embrace must not have escaped Mr. Zelensky on Friday. He came for other reasons. Many Arab leaders depend on Ukrainian grains to feed their people, he reminded them. Moreover, Kyiv puts a premium on showing that unlike Mr. Putin, the Ukrainian president’s appeal is global. 

“It’s one thing to go to the national assembly in Paris or the house of commons in London. It’s another thing that you go and say 143 countries believe” in your cause, Kyiv’s ambassador to the United Nations, Sergiy Kyslytsya, told the Sun recently. 

He was explaining the rationale for conducting declarative but unenforceable pro-Ukraine resolutions at the UN general assembly. A handful of countries support Russia in such votes, Mr. Kyslytsya noted, “so why should any country be together with just those four that support Russia?” 

Yet, Kyiv understands that beyond marshaling global support its ultimate goal is forcefully expelling the Russian invader. At Hiroshima, Mr. Zelensky is expected to meet invited guests from India, Indonesia, and others, as well as the world’s top leaders.

Japan and Riyadh are stops on a diplomatic spring offensive, which must lead to a long-expected military counterattack on the Russian forces. The Arab League is a good example of the perils of battlefield failure. 

In 2014, after Mr. Putin invaded Crimea, Russia was expelled from the G-7. Mr. Assad shows that unless a leader is militarily quashed, such isolation may well be temporary.