The Israel-Hamas war, conflict in Ukraine and rising tensions in the Indo-Pacific and Africa herald "what is likely to be a more dangerous decade," a British military think-tank warned Tuesday.

The International Institute for Strategic Studies (IISS) said in its annual "Military Balance" report that the world has entered "a highly volatile security environment".

"The current military-security situation heralds what is likely to be a more dangerous decade, characterised by the brazen application by some of military power to pursue claims," the report said.

The "era of insecurity" is resetting the global defence-industrial landscape, with the United State and Europe ramping up production of missiles and ammunition "after decades of underinvestment," the report added.

As the two-year anniversary of Russia's invasion of Ukraine looms, the London-based IISS reported that Moscow had lost around 3,000 battle tanks in the conflict, roughly the same number it had at the beginning of its operation.

Russia has traded "quality for quantity" in replacing the lost tanks and will only be able to sustain such losses for another two to three years, Bastian Giegerich, IISS director general, said at the report's release.

Ukraine, so far, has been able to offset equipment losses through Western donations, upgrading quality in the process, added the think-tank in its yearly assessment of the militaries and defence economics of over 170 countries.

But "western governments find themselves once again in a position where they must decide whether to furnish Kyiv with enough weapons to deliver a decisive blow or merely enough not to lose," added Giegerich.

It is therefore "incredibly vital" that the US passes a package releasing $60 billion of funding for Ukraine's war effort, Fenella McGerty, IISS defence economics specialist, told AFP.

The US Senate approved an aid bill on Tuesday but the legislation but if faces opposition from the Republican majority in the House of Representatives upper chamber.

Failure to pass the bill "would require a complete rethink about the goals and tactics used, because that funding would be very difficult for Europe to make up," McGerty warned.

NATO 'reinvigorated'

Driven in part by NATO's response to Russia's invasion, global military spending grew by 9 percent in 2022 to reach a record $2.2 trillion, noted the report.

"The security outlook has definitely deteriorated and we're seeing countries respond to that," said McGerty.

Republican presidential hopeful Donald Trump said on Saturday he had told one NATO member's leader that he would "encourage" Russia to "do whatever the hell they want" to that country if it had not met its NATO financial obligations.

"You got to pay. You got to pay your bills," Trump recounted at a campaign rally.

Only 10 members of the security alliance met the group's target of spending two percent of GDP on defence, although 19 of them increased spending last year, according to IISS figures.

"Russia's actions have reinvigorated NATO, with Finland completing its rapid alliance accession process in April 2023," the report noted.

"Russia's border with NATO members is now more than 1,300 kilometres longer."

Elsewhere, unrest related to the Gaza conflict risked speading having already affected Yemen, the Red Sea, Lebanon, Iraq and Syria, warned Ben Barry, a land warfare expert at IISS and a retired British army brigadier.

"All those conflicts carry with them the risk of escalation," he told AFP.

"The longer the war goes on, the more the chance there is of an accident... leading to retaliation," he added.

The report said Iran's supply of missiles to Huthi rebels in Yemen and drones to Russia highlighted Tehran's growing role in conflict zones.

China had also demonstrated "increased power-projection capacity", it added.

Western governments were now treating China as the world's greatest "pacing threat", said Douglas Barrie, IISS military aerospace specialist, with western demand driven by attempts to keep up with Chinese modernisation.