The US military has a substantial force of warships and fighter aircraft stationed across the Middle East and is moving even more firepower into the region as it braces for an increase in conflict.
The Middle East, already in turmoil after almost a year of fighting, was further rocked by Israel's killing of Hassan Nasrallah, the longtime leader of the Iran-backed militant group Hezbollah, in a massive airstrike in the Lebanese capital of Beirut on Friday.
The assassination of Nasrallah marked a major escalation in the yearlong conflict between Israel and the group and came amid increased Israeli military pressure on Hezbollah, raising concerns that the two bitter enemies could be heading toward an all-out war that could draw in US forces and perhaps even Iran.
The US has publicly said that it's ready to defend Israel and protect its forces in the Middle East from any attack by Iran or its regional proxies.
Amid increases in the intensity of the fighting, the US was already bracing for further violence. In a statement on Nasrallah's death, President Joe Biden said Saturday that he had directed Secretary of Defense Lloyd Austin the day before to "further enhance the defense posture of US military forces in the Middle East region to deter aggression and reduce the risk of a broader regional war."
The Pentagon's press secretary, Maj. Gen. Pat Ryder, then said on Sunday that the US "retains the capability to deploy forces on short notice." He added that the military maintained a "significant" presence in the region and could adjust its force posture "based on the evolving security situation."
As part of these efforts, Ryder said Austin directed the Abraham Lincoln Carrier Strike Group to remain in the Middle East region, where it has been operating for several weeks. The strike group consists of the aircraft carrier USS Abraham Lincoln and several destroyers.
Austin also ordered the Wasp Amphibious Ready Group to stay in the Eastern Mediterranean, where it has been for several months.
This assortment includes the multipurpose amphibious assault ship USS Wasp and its embarked 24th Marine Expeditionary Unit, which can be deployed to evacuate Americans. Additionally, the group has a dock landing ship and an amphibious-transport-dock vessel.
Beyond the carrier strike group and amphibious ready group, the US Navy has destroyers operating in the Middle East and the Eastern Mediterranean.
The American warships are complemented by land-based aircraft, including F-22s, F-15s, F-16s, and A-10s delivering fifth-generation stealth and fourth-generation combat capabilities, as well as proven ground-attack options. Ryder said the US would "further reinforce our defensive air-support capabilities in the coming days."
"The Secretary has also increased the readiness of additional US forces to deploy, elevating our preparedness to respond to various contingencies," Ryder said.
The Pentagon disclosed on Monday that it was sending more forces, including fighter squadrons, to the region. It previously said it would send a small number of additional troops, but the details weren't clear.
The changes to US force posture in the region followed a massive uptick in Israeli military pressure on Hezbollah, which began earlier in the month after a sophisticated pager attack that Israel is suspected of carrying out. It has now launched devastating airstrikes targeting militant assets. Scores of civilians have also been killed and wounded.
The Israeli strikes have dealt a serious blow to Hezbollah, including eliminating its leadership, but the heavily armed militant group has suggested that it is still ready for war.
Israeli officials, meanwhile, continue to hint that the country is gearing up for an expanded ground invasion of Lebanon, which would be Israel's first such operation since 2006 and mark another major escalation in the conflict.
"The elimination of Nasrallah is a very important step, but it is not the final one," Israeli Defense Minister Yoav Gallant told troops near the northern border with Lebanon on Monday.
"Our goal is to ensure the [safe] return of Israel's northern communities to their homes. We are prepared to make every effort necessary to accomplish this mission," Gallant said. "We will use all the means that may be required — your forces, other forces, from the air, from the sea, and on land."
It is unclear whether a final decision on the ground invasion has been made. On Monday, it was reported that Israeli special-operations forces were conducting raids into Lebanon, perhaps in preparation for an invasion. Diplomatic efforts to bring Israel and Hezbollah to the negotiating table have been unsuccessful.