STUTTGART, Germany -- A task force led by the former head of U.S. troops in Europe is recommending a beefed up American military force in Poland, home-porting Navy destroyers in Denmark and other steps to muscle up against a Russian military that has allies outgunned in the east.

Gen. Philip Breedlove, who led U.S. European Command and served as NATO supreme allied commander until retiring in 2016, warned in a new report that alliance "trip-wire" forces in the Baltics and Poland could be overrun if attacked.

"A determined Russian conventional attack, especially if mounted with little warning, could defeat these forward-deployed NATO and U.S. forces in a relatively short period of time, before reinforcements could be brought to bear," stated the Atlantic Council report co-authored by Breedlove.

A quick Russian land grab "might present the Alliance with a fait accompli, dividing the Alliance and paralyzing decision-making before reinforcements could arrive," the December report said.

The report, called "Permanent Deterrence: Enhancements to the U.S. Military Presence in North Central Europe," lays out a plan to counter such scenarios. It reiterates concerns raised by numerous security analysts in recent years -- chiefly that Russia's military advantage on NATO's eastern flank means it could quickly overrun allies in places such as the Baltics. But it also makes recommendations that go beyond the usual calls for another Army brigade in Europe as the answer to a mismatch with Russia.

Breedlove, a chief architect of NATO's buildup in reaction to Russia's 2014 intervention in Ukraine, sees a larger role for the U.S. military in Poland.

"Many of the recommended enhancements would take place in Poland, because its size and geographic location make it a key staging area for most NATO efforts to defend allied territory in the three Baltic states," stated the report, which Breedlove authored with task force co-chair and former NATO deputy secretary-general Alexander Vershbow.

The report comes amid a congressionally mandated military review that is examining whether the U.S. has sufficient forces in Europe to deter Russia. That review also is taking place as the Pentagon considers a $2 billion offer from Poland to fund a permanent base in that country.

However, it is unclear how seriously considered the recommendations will be in light of upheaval at the Pentagon, where Defense Secretary Jim Mattis, a strong advocate of maintaining alliance ties, has tendered his resignation. President Donald Trump has frequently complained about the large numbers of troops overseas. The future composition of forces in Europe could depend on the view of Mattis' yet unnamed permanent replacement.

Larger role for Army, Navy

One recommendation by the Atlantic Council task force is to expand a U.S. Army mission command headquarters in Poznan, Poland, into a division-sized element, and make it a permanent mission. The headquarters would by charged with ensuring the rapid flow of U.S. reinforcements to Poland and the Baltic states in time of crisis.

Breedlove also envisions a larger role for the Navy on the continent.

During the past four years, most of the buildup in Europe has centered on Army initiatives, such as the continuous deployment of U.S.-based brigades to the Continent and the expansion of weapons stocks at strategic locations.

While the Atlantic Council task force calls for more similar efforts, the Pentagon should consider adding a small naval detachment in Gdynia, Poland, to facilitate more Navy visits to Poland and to other Baltic Sea ports, the report said.

The U.S. also should also seek to home-port Navy destroyers in Denmark, which would allow continuous patrols in the Baltic Sea.

"The mission might include anti-submarine warfare, maritime domain awareness, amphibious operations" and assets designed to counter an enemy strategy of denying access to the seas, the report said.

Home-porting ships in Denmark rather than Poland would avoid coming into conflict with the 1997 NATO-Russia Founding Act, which sought to reassure Moscow that allies wouldn't position large combat formations in former Warsaw Pact nations on a permanent basis.

Allies such as Germany have made clear they want to honor the agreement, though critics say it should be dissolved because of Russia's military actions in Ukraine.

More land, drone forces

The Atlantic Council report recommends a mix of rotational and permanent forces.

"Measures along the lines proposed by the task force would build on the existing U.S. presence in Poland, strengthen deterrence for the wider region, and promote greater burden-sharing among allies," the report said. "While adding important military capabilities and increasing NATO's capacity for rapid reinforcement, the scale of the proposed measures should remain within the NATO consensus, thereby ensuring continued NATO cohesion and solidarity."

Meanwhile, the U.S. Air Force mission in Lask, Poland, should be enlarged to support rotational deployments of U.S. fighter and cargo aircraft, as well as possible aviation deployments by other allies, the report said.

An MQ-9 reconnaissance drone detachment at Miroslawiec Air Base, Poland, also should be permanent, according to the task force analysis. In Poland, a mid-range air-defense system also should be installed to protect U.S. soldiers deployed there.

The Atlantic Council review also calls for another Army brigade deployed to Europe either permanently or on rotation. The brigade, which would be based in Germany with elements in Poland, would be in addition to a rotational brigade already in Europe.

Whether those assets would be enough to blunt a Russian invasion isn't clear. A Rand Corp. report in 2016 said the minimum requirement would be seven NATO brigades, including three heavy armored brigades, supported by air power, land-based fire support and troops ready to fight at the onset of hostilities.

Any additional boosts to the military mission in Poland and around the Baltics would likely be met with condemnations and counteractions from Russia. Moscow has repeatedly said it has no designs on NATO territory but allies in the region remain unconvinced.

The task force, however, concluded a more robust force is more likely to deter possible Russian military adventurism on NATO turf.

"The task force strongly recommends that the United States, Poland, and the rest of the Alliance move forward on this basis," the report said.