Biden says that the US will back Ukraine for a decade. It may prove a hollow promise.

• US President Joe Biden at the G7 pledged a decade of security support for Ukraine.
• He said the US was not "backing down" in helping Ukraine fight Russia.

At the G7 summit in Italy on Thursday, Ukraine's President Volodymyr Zelenskyy hailed a "historic" new 10-year security deal signed with US President Joe Biden.

Under the deal, the US will work with Ukraine for the next decade to boost its military capabilities, its defense industrial base, its economy, and its energy infrastructure.

The G7 also provided Ukraine with a much-needed $50 billion loan, which will be paid back using interest on frozen Russian assets.

A war of attrition

"We're not backing down," Biden said, warning Russia's President Vladimir Putin that "he cannot wait us out."

The move is an apparent response to Russian President Vladimir Putin's strategy for wearing down Ukrainian resistance and the support of its allies by waging a drawn-out war of attrition.

Putin on Friday said he'd be willing to discuss a peace deal in Ukraine if Kyiv renounces its bid for Nato membership and withdraws its troops from four contested regions.

Analysts warn that the Russian president's claims to be seeking peace talks ought to be treated with skepticism. Ukraine is also highly unlikely to accept such conditions.

It seems the war will continue to be a long, drawn-out conflict.

Hollow promises

US support is key to preventing a Ukrainian defeat. However, the US security deal stops short of providing Ukraine with the path to NATO membership it's long requested.

The pledge signed by Biden is also an "executive agreement, rather than a formal treaty, meaning it can undone by a future president.

Republican candidate Donald Trump holds a narrow lead over Biden in recent polls and has offered, at best, ambiguous commitments to continue helping to defend Ukraine if elected.

He's criticized the amount of money the US is spending on the war and promised to end it, yet offered few details on how.

The deal also contains few concrete financial pledges, instead committing the White House to work with Congress to secure the funding to meet its security commitments to Ukraine.

This won't prove easy. For several months in 2023 and early 2024, a faction of isolationist Republicans in Congress held up a $61 billion Ukraine aid bill.

During that time, Ukraine saw its ammunition supplies running perilously low, and Russia threatened to break through Ukrainian defensive lines.

A divided Congress

In a Congress starkly divided along partisan lines, Biden, even if he wins in November, may find it difficult to build a consensus for new Ukraine aid bills.

Zelenskyy acknowledged the difficulties in his remarks at the G7. "For how long will the unity in the world remain? The unity in the US, together with European leaders," he said, with elections scheduled in several states that have provided support for Ukraine.

But Zelenskyy had a stark warning on the potential consequences if Western countries fail to meet their commitment to help Ukraine battle Russian aggression.

"If Ukraine does not withstand, the democracy of many countries, I am sure, won't withstand either," he said.