Galvanizing support by warning about an imminent Russian invasion, Ukrainian President Petro Poroshenko managed to win approval from the Ukrainian Parliament in a midnight vote on Monday following five hours of contentious debate.

Unwilling to simply accept Poroshenko's claims that he had heard reliable whispers about an imminent Russian invasion, opposition figures pressed Poroshenko on his reasoning for the emergency measures, and ultimately succeeded in forcing him to water down the proposal. But even before Poroshenko's decree won the approval of lawmakers, the Ukrainian president had already started deploying troops into the streets of his country.

Now in a state of martial law, Ukraine has called up its reservists and deployed all available troops to join the mobilization. Initially expected to last for two months, Poroshenko revised his degree to avoid accusations that he would try to interfere in the upcoming Ukrainian election. The decree passed by the Rada will leave martial law in effect for 30 days. The country has also started restricting travel for Russian nationals. NATO Commander Jens Stoltenberg told the Associated Press that Poroshenko had given his word that the order wouldn't interfere with the upcoming vote.

#BREAKING: After hours of debate the #Ukrainian Parliament has just voted on activating Martial Law for 30 days beginning November 28. Reservists will be called up as a part of it. #Russia #Ukraine — Instant News Alerts (@InstaNewsAlerts) November 26, 2018

The conflict between the Ukraine and Russia exploded into life on Sunday when Russian ships fired on two Ukrainian artillery ships and rammed a tugboat as the ships traveled toward the Kerch Strait, which connects the Sea of Azov to the Black Sea. Russia's mighty Black Sea fleet has taken the three ships and their crew into custody, and has so far ignored calls to release the soldiers by the UN, European leaders and Poroshenko himself.

US officials criticized Russia for its "aggressive" defense of the Kerch Strait, which Ukraine has a right to use according to a bilateral treaty. After Nikki Haley said during an emergency meeting of the UN Security Council that Russia was making it "impossible" to have normal relations with the US, Mike Pompeo said Russia's "aggressive action" was a "dangerous escalation" and also "violates international law." He also advocated for Poroshenko and Russian President Vladimir Putin to engage in direct talks.

Russia says the ships disobeyed orders to halt, and that Ukraine had failed to notify Russia of the ships' advance. Ukraine claims that it did notify Russia, and that the incident is the result of "growing Russian aggression." Six Ukrainian crewmen were injured in the Russian attack, which was the first act of violence between the two nations since the annexation of Crimea.

Chief diplomats from both countries traded accusations of provocations and "deliberate hostility."

Ukrainian Foreign Minister Pavlo Klimkin tweeted that the dispute was not an accident and that Russia had engaged in "deliberately planned hostilities," while Russian Foreign Minister Sergey Lavrov blamed Kiev for what he described as a "provocation," adding that "Ukraine had undoubtedly hoped to get additional benefits from the situation, expecting the U.S. and Europe to blindly take the provocateurs’ side."

Poroshenko said the martial law was necessary because Ukraine was facing nothing short of a all-out ground invasion.

Poroshenko said it was necessary because of intelligence about "a highly serious threat of a ground operation against Ukraine." He did not elaborate. "Martial law doesn’t mean declaring a war," he said. "It is introduced with the sole purpose of boosting Ukraine’s defense in the light of a growing aggression from Russia."

But the president's plans to impose martial law throughout the country were rebuffed as the opposition forced a compromise where troops will only be deployed in 10 border provinces. These provinces share borders with Russia, Belarus and the Trans-Dniester, a pro-Moscow breakaway region of Moldova.

Still, many remained skeptical. Opposition figures, including former President Yulia Tymoshenko pointed out that the order would give soldiers broad latitude to do pretty much whatever they want. Furthermore, Ukraine never called for martial law during the insurgency in the east that erupted back in 2014, eventually leading to an armed conflict that killed more than 10,000.

The approved measures included a partial mobilization and strengthening of air defenses. It also contained vaguely worded steps such as "strengthening" anti-terrorism measures and "information security" that could curtail certain rights and freedoms. But Poroshenko also pledged to respect the rights of Ukrainian citizens. [...] Despite Poroshenko’s vow to respect individual rights, opposition lawmaker and former Prime Minister Yulia Tymoshenko warned before the vote that his proposal would lead to the possible illegal searches, invasion of privacy and curtailing of free speech. "This means they will be breaking into the houses of Ukrainians and not those of the aggressor nation," noted Tymoshenko, who is leading in various opinion polls. "They will be prying into personal mail, family affairs ... In fact, everything that is written here is a destruction of the lives of Ukrainians." Poroshenko’s call also outraged far-right groups in Ukraine that have advocated severing diplomatic ties with Russia. Hundreds of protesters from the National Corps party waved flares in the snowy streets of Kiev outside parliament and accused the president of using martial law to his own ends. But Poroshenko insisted it was necessary because what happened in the Kerch Strait between Crimea and the Russian mainland "was no accident," adding that "this was not the culmination of it yet."

His critics reacted to his call for martial law with suspicion, wondering why Sunday’s incident merited such a response. With his approval ratings in free fall following a series of corruption scandals, Poroshenko's enemies worry that the incident may have been stage-managed to give the president an excuse to crack down on dissent and free movement ahead of the vote.