The latest American weapons package for Ukraine, unveiled on Friday, includes the longest range weapons yet to push back Russian troops and strike logistical targets well behind enemy lines. But they come with a hitch: They will be deployed on the battlefield too late to be used against a broad assault by Moscow that seemingly has begun to unfurl in eastern Ukraine.
That is also the case with most of the Western tanks, fighting vehicles and air-defense missiles that have been promised after months of pleas by President Volodymyr Zelensky of Ukraine.
Most of the sophisticated weapons will also require rigorous training for Ukrainian troops, who have never used them, a process that usually takes months and sometimes as long as a year.
And some of the arms — like the rocket-propelled guided bombs that the United States is now offering in the $2.17 billion package — have to be retrofitted from existing stocks or even built from scratch.
Already, Ukrainian forces are struggling to hold territory against Russia’s latest offensive, and Moscow is believed to be mobilizing at least 200,000 additional soldiers and possibly more.
“It is a race for time now,” said Heinrich Brauss, a former NATO assistant secretary general for defense policy and force planning.
Here is a look at the weapons that have been promised, and how long it will take for them to arrive.
Which weapons are on the way?
NATO states have already delivered tens of billions of dollars in weapons to Ukraine since the start of the war on Feb. 24, 2022. But Mr. Zelensky has pushed in particular for Patriot air defense systems to protect infrastructure from Russian airstrikes, and Western main battle tanks and infantry fighting vehicles for ground combat.
Last week, he also renewed his request for F-16 fighter jets that could potentially down Russian cruise missiles or could otherwise clear Ukraine’s airspace. Over the last two months alone, the United States and its allies have given in on almost all Ukraine’s weapons requests but the jets.
“Since Russia is four times as populous as Ukraine, the Ukrainian armed forces need Western weapons to overmatch the Russian armed forces technologically, or else Ukraine will lose the war,” said Peter W. Mansoor, a retired Army colonel and armor officer who is now a military historian at Ohio State University.
But few of them are expected to arrive any time soon.
Why will it take so long?
That varies from weapon to weapon. In the case of the longer-range missiles that were pledged Friday, most haven’t even been built yet.
Relatively cheap and usable in rocket launchers that have already been sent to Ukraine, these weapons, known as Small Diameter Bombs, are the Biden administration’s answer to Mr. Zelensky’s request for long-range munitions — without sending the most sophisticated American missiles that officials fear could be used to strike Russian territory.
Brigadier Gen. Pat Ryder, a Pentagon spokesman, said Friday that the bombs will help Ukraine “to conduct operations in defense of their country and to take their sovereign territory in Russian occupied areas.”
The weapons are actually two different munitions: a 250-pound bomb attached to an older type of rocket. They were developed by Boeing and Saab several years ago and are not currently being used by American troops.
Bradley Bowman, a former U.S. Army officer and senior military expert at the Foundation of Defense of Democracies in Washington, said it is likely to be nine months before even a modest shipment of 24 bombs and two launchers could reach Ukraine. Once production is up and running, he said, manufacturers could ship as many as 750 bombs and 12 launchers to Ukraine by the end of 2024.
“The bottom line is, yes, it will take some time,” said Mr. Bowman.
But, he said, that was not a reason to withhold the bombs.
“No one knows how long this war will last,” Mr. Bowman said, adding that it could end next week or last for 20 years.
Most of the other weapons that have been promised require special training.
How long will training last?
That largely depends on the weapon, and each country is working under its own timelines.
The estimated 100 tanks that Britain, Germany, Poland, the United States and at least a half-dozen other NATO states have so far pledged generally require at least three months, and sometimes up to a year, of training, according to American and European officials and military experts.
But officials are trying to condense training on German-made Leopard 2 tanks to a matter of weeks. Western defense officials have said they would aim to complete the training in about six weeks for the hundreds of Ukrainian soldiers who are already beginning to arrive in Germany and Poland, according to a European defense official and as was first reported by the Financial Times.
The first unit of Ukrainian soldiers to be trained on British-made Challenger 2 tanks arrived in the United Kingdom this week, the Defense Ministry said on Twitter. The United States has not said when its training will begin on its M1 Abrams tanks.
Ukrainian troops also need training on the sophisticated Patriot air-defense systems to guard against Russian attacks on power grids and other infrastructure.
The United States and Germany have each committed to sending Ukraine one Patriot battery, generally including trucks with radar, control systems, a generator and launching stations that can fire multiple missiles at a time. The Netherlands is also sending part of a Patriot system.
In the United States, training for about 100 Ukrainian troops began at an Army base in Oklahoma in mid-January and is “expected to last several months,” General Ryder said last month. Germany is training about 70 Ukrainians on the Patriot systems, said an official in Berlin. France and Italy announced on Friday they would send air defense systems that are similar to Patriot missiles, but did not say when or how many.
Will Ukraine get any of the new weapons soon?
Deliveries of some armored combat vehicles that were promised last month appear to be only days away.
The French defense minister, Sébastien Lecornu, said last week that the first of the AMX-10 combat reconnaissance vehicles that Paris has promised could be delivered in early February.
An initial tranche of armored Bradley Fighting Vehicles from the United States was headed to a North Sea port on their way to Ukraine, a second European defense official said this week. Additionally, German forces began training Ukraine troops last week on the Marder fighting vehicle that Berlin has promised.
What about the tanks?
Tanks will take longer, in part because of their lengthier training programs, but also because it will require time to transport and position the heavy war machines in the battlefield.
The process is inherently unpredictable. Last week, Alex Chalk, a senior British Defense Ministry official, told Parliament that the Challenger tanks could be in Ukraine at the end of March. Days later, the Defense Minister, Ben Wallace, told lawmakers those tanks would be delivered in “May, or probably toward Easter time” in early April.
The German defense minister, Boris Pistorius, initially predicted it would take three months for Berlin’s Leopards to reach Ukraine, then said they could arrive by late March or early April.
The Pentagon has been far more bullish about its timeline for delivering the Abrams tanks, and a spokeswoman, Sabrina Singh, told reporters last week that “it is going to take months.”
Ukraine can outmatch Russia “with the weapons it has been promised,” Mr. Mansoor said, “but not likely until late summer at the earliest.”
What about the fighter jets?
So far, Ukraine’s requests for F-16s have been rejected by President Biden and by Chancellor Olaf Scholz of Germany.
That could change: Both leaders have relented to Ukraine’s requests as the war grows more dire, and other NATO states signal they would send their own warplanes if Washington and Berlin took the lead. But even if they are approved, it will take Ukrainian pilots a “couple of weeks” to learn how to fly the jets and “about six months” to master how to fight with the aircraft, Yurii Ihnat, the spokesman for the Ukrainian Air Force, said in a briefing last week.
Mr. Brauss, the former NATO official and a retired German general, said Russia is likely to try to seize the momentum in the war before the Western weapons reach the battlefield.
“So much time has been wasted,” he said.
Eric Schmitt, John Ismay and Christopher F. Schuetze contributed reporting.